CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Other Comprehensive Income	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2018		52,477,593
Beginning balance at Dec. 31, 2018	$ 275,422	$ 52	$ 611,587	$ 1	$ (336,218)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock form the exercise of stock options and settlement of restricted stock units (in shares)		485,083
Issuance of common stock from the exercise of stock options and settlement of restricted stock units	179	$ 1	178
Stock-based compensation expense	3,282		3,282
Net income (loss)	(612)				(612)
Other comprehensive income (loss), net of tax	134			134
Ending balance (in shares) at Mar. 31, 2019		52,962,676
Ending balance at Mar. 31, 2019	278,405	$ 53	615,047	135	(336,830)
Beginning balance (in shares) at Dec. 31, 2018		52,477,593
Beginning balance at Dec. 31, 2018	275,422	$ 52	611,587	1	(336,218)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	111,337
Other comprehensive income (loss), net of tax	210
Ending balance (in shares) at Sep. 30, 2019		53,333,211
Ending balance at Sep. 30, 2019	400,907	$ 53	625,524	211	(224,881)
Beginning balance (in shares) at Mar. 31, 2019		52,962,676
Beginning balance at Mar. 31, 2019	278,405	$ 53	615,047	135	(336,830)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock form the exercise of stock options and settlement of restricted stock units (in shares)		302,108
Issuance of common stock from the exercise of stock options and settlement of restricted stock units	3,411	$ 0	3,411
Stock-based compensation expense	3,101		3,101
Net income (loss)	11,526				11,526
Other comprehensive income (loss), net of tax	251			251
Ending balance (in shares) at Jun. 30, 2019		53,264,784
Ending balance at Jun. 30, 2019	296,694	$ 53	621,559	386	(325,304)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock form the exercise of stock options and settlement of restricted stock units (in shares)		68,427
Issuance of common stock from the exercise of stock options and settlement of restricted stock units	558	$ 0	558
Stock-based compensation expense	3,407		3,407
Net income (loss)	100,423				100,423
Other comprehensive income (loss), net of tax	(175)			(175)
Ending balance (in shares) at Sep. 30, 2019		53,333,211
Ending balance at Sep. 30, 2019	$ 400,907	$ 53	625,524	211	(224,881)
Beginning balance (in shares) at Dec. 31, 2019	53,549,612	53,549,612
Beginning balance at Dec. 31, 2019	$ 410,945	$ 54	631,307	249	(220,665)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock form the exercise of stock options and settlement of restricted stock units (in shares)		582,724
Issuance of common stock from the exercise of stock options and settlement of restricted stock units	479	$ 0	479
Stock-based compensation expense	3,944		3,944
Net income (loss)	486				486
Other comprehensive income (loss), net of tax	532			532
Ending balance (in shares) at Mar. 31, 2020		54,132,336
Ending balance at Mar. 31, 2020	$ 416,386	$ 54	635,730	781	(220,179)
Beginning balance (in shares) at Dec. 31, 2019	53,549,612	53,549,612
Beginning balance at Dec. 31, 2019	$ 410,945	$ 54	631,307	249	(220,665)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	15,147
Other comprehensive income (loss), net of tax	$ 130
Ending balance (in shares) at Sep. 30, 2020	54,689,654	54,689,654
Ending balance at Sep. 30, 2020	$ 440,572	$ 55	645,656	379	(205,518)
Beginning balance (in shares) at Mar. 31, 2020		54,132,336
Beginning balance at Mar. 31, 2020	416,386	$ 54	635,730	781	(220,179)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock form the exercise of stock options and settlement of restricted stock units (in shares)		496,000
Issuance of common stock from the exercise of stock options and settlement of restricted stock units	3,600	$ 1	3,599
Stock-based compensation expense	3,069		3,069
Net income (loss)	8,714				8,714
Other comprehensive income (loss), net of tax	(185)			(185)
Ending balance (in shares) at Jun. 30, 2020		54,628,336
Ending balance at Jun. 30, 2020	431,584	$ 55	642,398	596	(211,465)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock form the exercise of stock options and settlement of restricted stock units (in shares)		61,318
Issuance of common stock from the exercise of stock options and settlement of restricted stock units	123	$ 0	123
Stock-based compensation expense	3,135		3,135
Net income (loss)	5,947				5,947
Other comprehensive income (loss), net of tax	$ (217)			(217)
Ending balance (in shares) at Sep. 30, 2020	54,689,654	54,689,654
Ending balance at Sep. 30, 2020	$ 440,572	$ 55	$ 645,656	$ 379	$ (205,518)