Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation - Stock Option Activity (Details)

v3.19.1
Stock-based Compensation - Stock Option Activity (Details) - Stock Options [Member]
$ / shares in Units, $ in Thousands
3 Months Ended
Mar. 31, 2019
USD ($)
$ / shares
shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]  
Number of shares, Outstanding at beginning of year | shares 1,624,746
Number of shares, Granted | shares 349,979
Number of shares, Exercised | shares (23,861)
Number of shares, Forfeited, expired or cancelled | shares (32,914)
Number of shares, Outstanding at end of year | shares 1,917,950
Number of shares, Exercisable at end of period | shares 1,134,601
Weighted Average Exercise Price Per Share, Outstanding at January 1, 2019 | $ / shares $ 23.09
Weighted Average Exercise Price Per Share, Granted | $ / shares 14.23
Weighted Average Exercise Price Per Share, Exercised | $ / shares 4.83
Weighted Average Exercise Price Per Share, Forfeited, expired or cancelled | $ / shares 64.36
Weighted Average Exercise Price Per Share, Outstanding at March 31, 2019 | $ / shares 20.99
Weighted Average Exercise Price Per Share, Exercisable at March 31, 2019 | $ / shares $ 24.42
Weighted Average Contractual Term (in years), Outstanding at March 31, 2019 7 years 10 months 24 days
Weighted Average Contractual Term (in years), Exercisable at March 31, 2019 7 years 1 month 6 days
Aggregate Intrinsic Value, Outstanding at March 31, 2019 | $ $ 7,624
Aggregate Intrinsic Value, Exercisable at March 31, 2019 | $ $ 6,046