Annual report pursuant to Section 13 and 15(d)

Compensation and Other Benefit Plans - Weighted Average Assumptions (Details)

v3.8.0.1
Compensation and Other Benefit Plans - Weighted Average Assumptions (Details) - Stock Options [Member]
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Stock-based awards weighted average assumptions [Abstract]      
Dividend yield 0.00% 0.00% 0.00%
Expected volatility 100.00% 101.00% 84.00%
Risk-free interest rate 1.90% 1.84% 1.40%
Expected term 5 years 7 months 6 days 5 years 7 months 6 days 5 years 7 months 6 days