Quarterly report pursuant to Section 13 or 15(d)

Benefit Plans - Stock Options Activity Under Share-Based Payment Plans (Details)

v3.8.0.1
Benefit Plans - Stock Options Activity Under Share-Based Payment Plans (Details) - Employees and Non Employee Stock Option
$ / shares in Units, shares in Thousands, $ in Thousands
 3 Months Ended
Mar. 31, 2018
USD ($)
$ / shares
shares
Options  
Outstanding as of beginning of period (in shares) | shares 280,457
Granted (in shares) | shares 6,972
Exercised (in shares) | shares (19,088)
Forfeited, cancelled or expired (in shares) | shares (487)
Outstanding as of end of period (in shares) | shares 267,854
Exercisable (in shares) | shares 113,849
Weighted- Average Exercise Price Per Share  
Outstanding as of beginning of period (in dollars per share) | $ / shares $ 3.76
Granted (in dollars per share) | $ / shares 6.12
Exercised (in dollars per share) | $ / shares 3.20
Forfeited, cancelled or expired (in dollars per share) | $ / shares 4.68
Outstanding as of end of period (in dollars per share) | $ / shares 3.86
Exercisable (in dollars per share) | $ / shares $ 3.24
Weighted- Average Remaining Contractual Term (Years)  
Outstanding 6 years 6 months 11 days
Exercisable 5 years 2 months 1 day
Aggregate Intrinsic Value  
Outstanding | $ $ 638,150
Exercisable | $ $ 341,025