Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2019		39,251
Beginning balance at Dec. 31, 2019	$ 114,601	$ 393	$ 251,641	$ (136,473)	$ (960)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,337			3,337
Other comprehensive income (loss)	(1,434)				(1,434)
Stock option exercises and employee stock plan purchases (in shares)		33
Stock option exercises and employee stock plan purchases	366		366
Vesting of restricted stock awards and units (in shares)		563
Vesting of restricted stock awards and units	0	$ 6	(6)
Shares withheld to cover taxes (in shares)		(97)
Shares withheld to cover taxes	(1,547)	$ (1)	(1,546)
Stock-based compensation	3,075		3,075
Ending balance (in shares) at Mar. 31, 2020		39,750
Ending balance at Mar. 31, 2020	118,398	$ 398	253,530	(133,136)	(2,394)
Beginning balance (in shares) at Dec. 31, 2020		66,875
Beginning balance at Dec. 31, 2020	514,205	$ 669	665,530	(149,946)	(2,048)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	9,008			9,008
Other comprehensive income (loss)	808				808
Stock option exercises and employee stock plan purchases (in shares)		155
Stock option exercises and employee stock plan purchases	2,380	$ 1	2,379
Vesting of restricted stock awards and units (in shares)		489
Vesting of restricted stock awards and units	0	$ 5	(5)
Shares withheld to cover taxes (in shares)		(85)
Shares withheld to cover taxes	(1,599)	$ (1)	(1,598)
Stock-based compensation	3,317		3,317
Ending balance (in shares) at Mar. 31, 2021		67,434
Ending balance at Mar. 31, 2021	$ 528,119	$ 674	$ 669,623	$ (140,938)	$ (1,240)