| Pay vs Performance Disclosure - USD ($)
 | 12 Months Ended | 
| Dec. 31, 2022 | Dec. 31, 2021 | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Pay vs Performance [Table Text Block] | Pay Versus Performance Table As required by Section 953(a) of the Dodd-Frank Wall Street Reform and Consumer Protection Act and Item 402(v) of Regulation  S-K,  we are providing the following information about the relationship between executive compensation actually paid and certain financial performance of the Company. This disclosure is intended to comply with the requirements of Item 402(v) of Regulation  S-K  applicable to “smaller reporting companies.” For further information concerning the Company’s compensation philosophy and how the Company seeks to align executive compensation with the Company’s performance, refer to “Executive Compensation—Narrative Disclosure to Summary Compensation Table and Outstanding Equity Awards Table.”   
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|  |  | Summary Compensation Table Total for PEO (1)
 |  | Compensation Actually Paid to PEO (2)
 |  | Average Summary Compensation Table Total for Non-PEO  NEOs (3)
 |  | Average Compensation Actually Paid to Non-PEO NEOs (4)
 |  | Value of Initial Fixed $100 Investment Based on Total Stockholder Return (5)
 |  | Net (Loss) Income (millions) (6)
 |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
| 2022 |  |  | $ | 2,344,168 |  |  |  | $ | 2,344,168 |  |  |  | $ | 1,009,298 |  |  |  | $ | 956,887 |  |  |  | $ | 41.69 |  |  |  | ($ | 17.1 | ) |  
| 2021 |  |  | $ | 3,510,795 |  |  |  | $ | 3,510,795 |  |  |  | $ | 1,135,708 |  |  |  | $ | 349,707 |  |  |  | $ | 47.25 |  |  |  | $ | 15.8 |  |    
| (1) | The dollar amounts reported in column (b) are the amounts of total compensation reported for Mr. Neal (our Chief Executive Officer and PEO) for each corresponding year in the “Total” column of the Summary Compensation Table. Refer to “Executive Compensation—Summary Compensation Table.”  |  
| (2) | The dollar amounts reported in column (c) represent the amount of “compensation actually paid” to Mr. Neal, as computed in accordance with Item 402(v) of Regulation  S-K.  The dollar amounts do not reflect the actual amount of compensation earned by or paid to Mr. Neal during the applicable year. In accordance with the requirements of Item 402(v) of Regulation  S-K,  the following adjustments w ere  made to Mr. Neal’s total compensation for each year to determine the compensation actually paid:  |    
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|  |  | Reported SummaryCompensation
 Table Total for PEO
 |  | 
 
 |  | Equity Award Adjustments (b)
 |  | CompensationActually Paid
 to PEO
 |  
| 2022 |  |  | $ | 2,344,168 |  |  |  |  | — |  |  |  |  | — |  |  |  | $ | 2,344,168 |  |  
| 2021 |  |  | $ | 3,510,795 |  |  |  | ($ | 2,633,242 | ) |  |  | $ | 2,633,242 |  |  |  | $ | 3,510,795 |  |    
|  | (a) | The grant date fair value of equity awards represents the total of the amounts reported in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table for the applicable year.  |  
|  | (b) | The equity award adjustments for each applicable year include the addition (or subtraction, as applicable) of the following: (i) the  year-end  fair value of any equity awards granted in the applicable year that are outstanding and unvested as of the end of the year; (ii) the amount of change as of the end of the applicable year (from the end of the prior fiscal year) in fair value of any awards granted in prior years that are outstanding and unvested as of the end of the applicable year; (iii) for awards that are granted and vest in same applicable year, the fair value as of the vesting date; (iv) for awards granted in prior years that vest in the applicable year, the amount equal to the change as of the vesting date (from the end of the prior fiscal year) in fair value; (v) for awards granted in prior years that are determined to fail to meet the applicable vesting conditions during the applicable year, a deduction for the amount equal to the fair value at the end of the prior fiscal year; and (vi) the dollar value of any dividends or other earnings paid on stock or option awards in the applicable year prior to the vesting date that are not otherwise reflected in the fair value of such award or included in any other component of total compensation for the applicable year. The valuation assumptions used to calculate fair values did not materially differ from those disclosed at the time of grant. The stock option agreement granted in 2021 to Mr. Neal provided that if Mr. Neal met certain age and service criteria, he would be eligible to  |    
|  | “retire” and his option would become fully exercisable. At the time of grant, Mr. Neal had satisfied such retirement eligibility and the service-based vesting requirements were deemed to have been met. Therefore, the same fair value is being used for the equity award adjustment as was used for the Summary Compensation Table. The amounts deducted or added in calculating the equity award adjustments are as follows:  |    
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|  |  | Year EndFair
 Value of
 Outstanding
 and
 Unvested
 Equity
 Awards
 granted in
 the Year
 |  | Year overYear Change
 in
 Fair Value of
 Outstanding
 and
 Unvested
 Equity
 Awards
 Granted in
 Prior Years
 |  | Fair Valueas of Vesting
 Date of
 Equity
 Awards
 Granted and
 Vested in the
 Year
 |  | Year overYear
 Change in
 Fair Value
 of Equity
 Awards
 Granted
 in Prior
 Years that
 Vested in
 the Year
 |  | Fair Valueat the End
 of the
 Prior Year
 of Equity
 Awards
 that Failed
 to Meet
 Vesting
 Conditions
 in the Year
 |  | 
 
 
 
 |  
| 2022 |  |  |  | — |  |  |  |  | — |  |  |  |  | — |  |  |  |  | — |  |  |  |  | — |  |  |  |  | — |  |  
| 2021 |  |  |  | — |  |  |  |  | — |  |  |  | $ | 2,633,242 |  |  |  |  | — |  |  |  |  | — |  |  |  | $ | 2,633,242 |  |    
| (3) | The dollar amounts reported in column (d) represent the average of the amounts reported for the Company’s named executive officers (NEOs) as a group (excluding Mr. Neal, who has served as our CEO since 2016) in the “ Total” column of the Summary Compensation Table in each applicable year. Mr. Burns was the sole NEO (excluding Mr. Neal) included for purposes of calculating the average amounts in each applicable year.  |  
| (4) | The dollar amounts reported in column (e) represent the average amount of “compensation actually paid” to the NEOs as a group (excluding Mr. Neal), as computed in accordance with Item 402(v) of Regulation  S-K.  The dollar amounts do not reflect the actual average amount of compensation earned by or paid to the NEOs as a group (excluding Mr. Neal) during the applicable year. In accordance with the requirements of Item 402(v) of Regulation  S-K,  the following adjustments were made to average total compensation for the NEOs as a group (excluding Mr. Neal) for each year to determine the compensation actually paid, using the same methodology described above in Note (2):  |    
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|  |  | 
 Reported Summary Compensation Table Total for Non-PEO NEOs
 |  | 
 
 
 |  | 
 
 |  | Average Compensation Actually Paid to Non-PEO  NEOs
 |  
| 2022 |  |  | $ | 1,009,298 |  |  |  | ($ | 470,850 | ) |  |  |  | $418,439 |  |  |  | $ | 956,887 |  |  
| 2021 |  |  | $ | 1,135,708 |  |  |  | ($ | 599,719 | ) |  |  |  | ($186,282) |  |  |  | $ | 349,707 |  |    
|  | (a) | The amounts deducted or added in calculating the total average equity award adjustments are as follows:  |    
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|  |  | 
 FairValue of
 Outstanding
 and
 Unvested
 Equity
 Awards
 granted in
 
 |  | Year overYear Average
 Change in
 Fair Value of
 Outstanding
 and Unvested
 Equity
 Awards
 Granted in
 Prior Years
 |  | AverageFair
 Value as of
 Vesting Date
 of Equity
 Awards
 Granted and
 Vested in
 
 |  | Year overYear
 Average
 Change in
 Fair Value of
 Equity
 Awards
 Granted in
 Prior Years
 that Vested
 in the Year
 |  | Average FairValue at the
 End of the
 Prior Year of
 Equity Awards
 that Failed to
 Meet Vesting
 Conditions in
 the Year
 |  | AverageValue of
 Dividends or
 other
 Earnings Paid
 on Stock or
 Option
 Awards not
 Otherwise
 Reflected in
 Fair Value or
 Total
 Compensation
 |  | 
 
 
 
 
 |  
| 2022 |  |  | $ | 345,047 |  |  |  | ($ | 20,942 | ) |  |  | $ | 97,611 |  |  |  | ($ | 3,277 | ) |  |  | $ | 0 |  |  |  |  | — |  |  |  | $ | 418,439 |  |  
| 2021 |  |  | $ | 133,929 |  |  |  | ($ | 224,276 | ) |  |  | $ | 90,689 |  |  |  | ($ | 186,624 | ) |  |  | $ | 0 |  |  |  |  | — |  |  |  | ($ | 186,282 | ) |  
| (5) | Cumulative TSR is calculated by dividing the sum of the cumulative amount of dividends for the measurement period, assuming dividend reinvestment, and the difference between the Company’s share price at the end and the beginning of the measurement period by the Company’s share price at the beginning of the measurement period.  |  
| (6) | The dollar amounts reported represent the amount of net loss reflected in the Company’s audited financial statements for the applicable year. Due to the fact that the Company is a biotech royalty aggregator, our revenue is comprised of licensing fees, milestone payments and royalties from our legacy discovery and development business and future milestone payments and royalties from our royalty aggregator business. Consequently, we did not use net income (loss) as a performance measure in our executive compensation program. Moreover, because the generation of revenues related to licensing fees, milestone payments, and royalties is dependent on the achievement of milestones or product sales by our partners, we do not believe there is any meaningful relationship between our net income and compensation actually paid to our NEOs during the periods presented.  |  |  | 
| Named Executive Officers, Footnote [Text Block] | Mr. Burns was the sole NEO (excluding Mr. Neal) included for purposes of calculating the average amounts in each applicable year. |  | 
| PEO Total Compensation Amount | $ 2,344,168 | $ 3,510,795 | 
| PEO Actually Paid Compensation Amount | $ 2,344,168 | 3,510,795 | 
| Adjustment To PEO Compensation, Footnote [Text Block] | 
| (2) | The dollar amounts reported in column (c) represent the amount of “compensation actually paid” to Mr. Neal, as computed in accordance with Item 402(v) of Regulation  S-K.  The dollar amounts do not reflect the actual amount of compensation earned by or paid to Mr. Neal during the applicable year. In accordance with the requirements of Item 402(v) of Regulation  S-K,  the following adjustments w ere  made to Mr. Neal’s total compensation for each year to determine the compensation actually paid:  |    
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  | Reported SummaryCompensation
 Table Total for PEO
 |  | 
 
 |  | Equity Award Adjustments (b)
 |  | CompensationActually Paid
 to PEO
 |  
| 2022 |  |  | $ | 2,344,168 |  |  |  |  | — |  |  |  |  | — |  |  |  | $ | 2,344,168 |  |  
| 2021 |  |  | $ | 3,510,795 |  |  |  | ($ | 2,633,242 | ) |  |  | $ | 2,633,242 |  |  |  | $ | 3,510,795 |  |    
|  | (a) | The grant date fair value of equity awards represents the total of the amounts reported in the “Stock Awards” and “Option Awards” columns in the Summary Compensation Table for the applicable year.  |  
|  | (b) | The equity award adjustments for each applicable year include the addition (or subtraction, as applicable) of the following: (i) the  year-end  fair value of any equity awards granted in the applicable year that are outstanding and unvested as of the end of the year; (ii) the amount of change as of the end of the applicable year (from the end of the prior fiscal year) in fair value of any awards granted in prior years that are outstanding and unvested as of the end of the applicable year; (iii) for awards that are granted and vest in same applicable year, the fair value as of the vesting date; (iv) for awards granted in prior years that vest in the applicable year, the amount equal to the change as of the vesting date (from the end of the prior fiscal year) in fair value; (v) for awards granted in prior years that are determined to fail to meet the applicable vesting conditions during the applicable year, a deduction for the amount equal to the fair value at the end of the prior fiscal year; and (vi) the dollar value of any dividends or other earnings paid on stock or option awards in the applicable year prior to the vesting date that are not otherwise reflected in the fair value of such award or included in any other component of total compensation for the applicable year. The valuation assumptions used to calculate fair values did not materially differ from those disclosed at the time of grant. The stock option agreement granted in 2021 to Mr. Neal provided that if Mr. Neal met certain age and service criteria, he would be eligible to  |    
|  | “retire” and his option would become fully exercisable. At the time of grant, Mr. Neal had satisfied such retirement eligibility and the service-based vesting requirements were deemed to have been met. Therefore, the same fair value is being used for the equity award adjustment as was used for the Summary Compensation Table. The amounts deducted or added in calculating the equity award adjustments are as follows:  |    
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|  |  | Year EndFair
 Value of
 Outstanding
 and
 Unvested
 Equity
 Awards
 granted in
 the Year
 |  | Year overYear Change
 in
 Fair Value of
 Outstanding
 and
 Unvested
 Equity
 Awards
 Granted in
 Prior Years
 |  | Fair Valueas of Vesting
 Date of
 Equity
 Awards
 Granted and
 Vested in the
 Year
 |  | Year overYear
 Change in
 Fair Value
 of Equity
 Awards
 Granted
 in Prior
 Years that
 Vested in
 the Year
 |  | Fair Valueat the End
 of the
 Prior Year
 of Equity
 Awards
 that Failed
 to Meet
 Vesting
 Conditions
 in the Year
 |  | 
 
 
 
 |  
| 2022 |  |  |  | — |  |  |  |  | — |  |  |  |  | — |  |  |  |  | — |  |  |  |  | — |  |  |  |  | — |  |  
| 2021 |  |  |  | — |  |  |  |  | — |  |  |  | $ | 2,633,242 |  |  |  |  | — |  |  |  |  | — |  |  |  | $ | 2,633,242 |  |  |  | 
| Non-PEO NEO Average Total Compensation Amount | $ 1,009,298 | 1,135,708 | 
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 956,887 | 349,707 | 
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | 
| (4) | The dollar amounts reported in column (e) represent the average amount of “compensation actually paid” to the NEOs as a group (excluding Mr. Neal), as computed in accordance with Item 402(v) of Regulation  S-K.  The dollar amounts do not reflect the actual average amount of compensation earned by or paid to the NEOs as a group (excluding Mr. Neal) during the applicable year. In accordance with the requirements of Item 402(v) of Regulation  S-K,  the following adjustments were made to average total compensation for the NEOs as a group (excluding Mr. Neal) for each year to determine the compensation actually paid, using the same methodology described above in Note (2):  |    
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  | 
 Reported Summary Compensation Table Total for Non-PEO NEOs
 |  | 
 
 
 |  | 
 
 |  | Average Compensation Actually Paid to Non-PEO  NEOs
 |  
| 2022 |  |  | $ | 1,009,298 |  |  |  | ($ | 470,850 | ) |  |  |  | $418,439 |  |  |  | $ | 956,887 |  |  
| 2021 |  |  | $ | 1,135,708 |  |  |  | ($ | 599,719 | ) |  |  |  | ($186,282) |  |  |  | $ | 349,707 |  |    
|  | (a) | The amounts deducted or added in calculating the total average equity award adjustments are as follows:  |    
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  | 
 FairValue of
 Outstanding
 and
 Unvested
 Equity
 Awards
 granted in
 
 |  | Year overYear Average
 Change in
 Fair Value of
 Outstanding
 and Unvested
 Equity
 Awards
 Granted in
 Prior Years
 |  | AverageFair
 Value as of
 Vesting Date
 of Equity
 Awards
 Granted and
 Vested in
 
 |  | Year overYear
 Average
 Change in
 Fair Value of
 Equity
 Awards
 Granted in
 Prior Years
 that Vested
 in the Year
 |  | Average FairValue at the
 End of the
 Prior Year of
 Equity Awards
 that Failed to
 Meet Vesting
 Conditions in
 the Year
 |  | AverageValue of
 Dividends or
 other
 Earnings Paid
 on Stock or
 Option
 Awards not
 Otherwise
 Reflected in
 Fair Value or
 Total
 Compensation
 |  | 
 
 
 
 
 |  
| 2022 |  |  | $ | 345,047 |  |  |  | ($ | 20,942 | ) |  |  | $ | 97,611 |  |  |  | ($ | 3,277 | ) |  |  | $ | 0 |  |  |  |  | — |  |  |  | $ | 418,439 |  |  
| 2021 |  |  | $ | 133,929 |  |  |  | ($ | 224,276 | ) |  |  | $ | 90,689 |  |  |  | ($ | 186,624 | ) |  |  | $ | 0 |  |  |  |  | — |  |  |  | ($ | 186,282 | ) |  |  | 
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] |   |  | 
| Compensation Actually Paid vs. Net Income [Text Block] | Compensation Actually Paid and Net Income (Loss) As a biotech royalty aggregator, our revenue is comprised of licensing fees, milestone payments and royalties from our legacy discovery and development business and future milestone payments and royalties from our royalty aggregator business. Consequently, we did not use net income (loss) as a performance measure in our executive compensation program. Moreover, because the generation of revenues related to licensing fees, milestone payments, and royalties is dependent on the achievement of milestones or product sales by our partners, we do not believe there is any meaningful relationship between our net income and compensation actually paid to our NEOs during the periods presented.  |  | 
| Total Shareholder Return Amount | $ 41.69 | 47.25 | 
| Net Income (Loss) | $ (17,100,000) | 15,800,000 | 
| PEO Name | Mr. Neal |  | 
| PEO [Member] | Reported Value of Equity Awards [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount |  | (2,633,242) | 
| PEO [Member] | Equity Award Adjustments [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount |  | 2,633,242 | 
| PEO [Member] | Fair Value as of Vesting Date of Equity Awards Granted and Vested in the Year [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount |  | 2,633,242 | 
| PEO [Member] | Total Equity Award Adjustments [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount |  | 2,633,242 | 
| Non-PEO NEO [Member] | Reported Value of Equity Awards [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount | $ (470,850) | (599,719) | 
| Non-PEO NEO [Member] | Equity Award Adjustments [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount | 418,439 | (186,282) | 
| Non-PEO NEO [Member] | Year End Fair Value of Outstanding and Unvested Equity Awards Granted [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount | 345,047 | 133,929 | 
| Non-PEO NEO [Member] | Year over Year Change in Fair Value of Outstanding and Unvested Equity Awards Granted [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount | (20,942) | (224,276) | 
| Non-PEO NEO [Member] | Fair Value as of Vesting Date of Equity Awards Granted and Vested in the Year [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount | 97,611 | 90,689 | 
| Non-PEO NEO [Member] | Year over Year Change in Fair Value of Equity Awards Granted in Prior Years that Vested [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount | (3,277) | (186,624) | 
| Non-PEO NEO [Member] | Fair Value at the End of the Prior Year of Equity Awards that Failed to Meet Vesting Conditions [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount | 0 | 0 | 
| Non-PEO NEO [Member] | Total Equity Award Adjustments [Member] |  |  | 
| Pay vs Performance Disclosure [Table] |  |  | 
| Adjustment to Compensation Amount | $ 418,439 | $ (186,282) |