Equity Incentive Plans and Stock-Based Compensation (Details 2) - Options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Shares
Outstanding, at the beginning of the period	1,639,146	3,235,891	4,310,361
Options granted	40,000	80,000	711,479
Options exercised	(613,119)	(1,249,785)	(908,146)
Stock options forfeited	(101,816)	(426,960)	(877,803)
Outstanding, at the end of the period	964,211	1,639,146	3,235,891
Vested or expected to vest at the end of the period	961,925
Options exercisable at the end of the period	781,102
Weighted-Average Exercise Price
Outstanding at the beginning of the year	$ 11.37	$ 10.25	$ 9.78
Options granted	15.59	13.25	12.84
Options exercised (in dollars per share)	10.74	7.79	6.70
Options forfeited (in dollars per share)	19.41	13.71	13.73
Outstanding at the end of the period	11.08	$ 11.37	$ 10.25
Vested or expected to vest at the end of the period (in dollars per share)	11.08
Options exercisable at the end of the period (in dollars per share)	$ 10.51
Weighted-Average Remaining Contractual Term (in years)
Outstanding (in years)	5 years 14 days
Vested or expected to vest (in years)	5 years 10 days
Options exercisable (in years)	4 years 3 months 21 days
Aggregate Intrinsic Value
Outstanding	$ 6,151
Vested or expected to vest	6,143
Options exercisable	$ 5,432