Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss, Net of Tax [Member]	(Accumulated Deficit)/Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	(Accumulated Deficit)/Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Total
Balance at Dec. 31, 2017	$ 1	$ 179,020	$ (259)			$ (4,006)		$ 174,756
Balance (in shares) at Dec. 31, 2017	11,656		5
Stock-based Compensation Expense		6,782						6,782
Treasury stock purchases for restricted stock vests			$ (659)					(659)
Treasury stock purchases for restricted stock vests (in shares)			11
Issuance of Common Shares upon Stock Option and ESPP Exercise		2,719	$ 259					2,978
Issuance of Common Shares upon Stock Option and ESPP Exercise (in shares)	142		(5)
Issuance of Restricted Stock Awards (in shares)	65
Repurchase of Convertible Notes and Unwind of Call Option Overlay		(1,709)						(1,709)
(Losses)/Gains on Interest Rate Swap				$ (379)				(379)
Net (loss)/income						15,494		15,494
Balance at Dec. 31, 2018	$ 1	186,812	$ (659)	(379)	$ 2	11,488	$ 2	197,263
Balance (in shares) at Dec. 31, 2018	11,863		11
Stock-based Compensation Expense		9,217						9,217
Treasury stock purchases for restricted stock vests			$ (1,031)					(1,031)
Treasury stock purchases for restricted stock vests (in shares)			20
Issuance of Common Shares upon Stock Option and ESPP Exercise		5,738						5,738
Issuance of Common Shares upon Stock Option and ESPP Exercise (in shares)	136
Issuance of Restricted Stock Awards		(967)	$ 967
Issuance of Restricted Stock Awards (in shares)	106		(16)
(Losses)/Gains on Interest Rate Swap				(4,492)				(4,492)
Net (loss)/income						6,094		6,094
Balance at Dec. 31, 2019	$ 1	200,800	$ (723)	(4,871)	$ (8)	17,584	$ (8)	212,791
Balance (in shares) at Dec. 31, 2019	12,105		15
Stock-based Compensation Expense		12,936						12,936
Treasury stock purchases for restricted stock vests			$ (1,523)					(1,523)
Treasury stock purchases for restricted stock vests (in shares)			61
Issuance of Common Shares upon Stock Option and ESPP Exercise		618						618
Issuance of Common Shares upon Stock Option and ESPP Exercise (in shares)	21
Issuance of Restricted Stock Awards (in shares)	304
(Losses)/Gains on Interest Rate Swap				(6,566)				(6,566)
Net (loss)/income						(22,548)		(22,548)
Balance at Dec. 31, 2020	$ 1	$ 214,354	$ (2,246)	$ (11,437)		$ (4,972)		$ 195,700
Balance (in shares) at Dec. 31, 2020	12,430		76