Net Income per Share - Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net income	$ 6,177	$ 9,779	$ 21,760	$ 25,333
Basic:
Weighted-average shares of common stock outstanding	31,873	31,246	31,800	31,321
Shares used in computing basic net income per share	31,873	31,246	31,800	31,321
Effect of dilutive securities:
Restricted stock subject to vesting	444	694	414	637
Shares issuable for acquisition consideration (in shares)	310	219	238	239
Shares issuable for conversion of convertible senior notes (in shares)	22		57
Shares used in computing diluted net income per share	32,649	32,159	32,509	32,197
Basic net income per share (in dollars per share)	$ 0.19	$ 0.31	$ 0.68	$ 0.81
Diluted net income per share (in dollars per share)	$ 0.19	$ 0.30	$ 0.67	$ 0.79