CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Treasury Stock	Total
Balance at Dec. 31, 2016	$ 362	$ 322,191	$ (1,440)	$ (255,003)	$ (696)	$ 65,414
Balance (in shares) at Dec. 31, 2016	36,041,000
Increase (Decrease) in Stockholders' Equity
Cumulative effect of a change in accounting | ASU 2016-09		98		(98)
Net income (loss)				(104,671)		(104,671)
Share based compensation expense		12,929				12,929
Issuance of common stock upon vesting of restricted stock units	$ 3	(3)
Issuance of common stock upon vesting of restricted stock units (in shares)	331,000
Effect of shares withheld to cover taxes		(1,477)				(1,477)
Total other comprehensive (loss) income			(246)			(246)
Balance at Dec. 31, 2017	$ 365	333,738	(1,686)	(359,772)	(696)	(28,051)
Balance (in shares) at Dec. 31, 2017	36,372,000
Increase (Decrease) in Stockholders' Equity
Cumulative effect of a change in accounting | ASU 2014-09				(756)		(756)
Balance at Jan. 01, 2018	$ 365	333,738	(1,686)	(360,528)	(696)	(28,807)
Balance (in shares) at Jan. 01, 2018	36,372,000
Balance at Dec. 31, 2017	$ 365	333,738	(1,686)	(359,772)	(696)	(28,051)
Balance (in shares) at Dec. 31, 2017	36,372,000
Increase (Decrease) in Stockholders' Equity
Net income (loss)				(858)		(858)
Share based compensation expense		13,065				13,065
Issuance of common stock upon vesting of restricted stock units	$ 6	(6)
Issuance of common stock upon vesting of restricted stock units (in shares)	544,000
Effect of shares withheld to cover taxes		(2,906)				(2,906)
Issuance of common stock in connection with the exercise of stock options		64				64
Issuance in connection with the exercise of stock options (in shares)	5,000
Reclassification of certain tax effects from accumulated other comprehensive loss | ASU 2018-02			(363)	363
Total other comprehensive (loss) income			(2,482)			(2,482)
Balance at Dec. 31, 2018	$ 371	343,955	(4,531)	(361,023)	(696)	$ (21,924)
Balance (in shares) at Dec. 31, 2018	36,921,000					36,921,174
Increase (Decrease) in Stockholders' Equity
Cumulative effect of a change in accounting | ASU 2016-02				1,547		$ 1,547
Issuance of common stock in connection with the exercise of stock options	$ 371	343,955	(4,531)	(359,476)	(696)	(20,377)
Issuance in connection with the exercise of stock options (in shares)	36,921,000
Balance at Jan. 01, 2019						(20,377)
Balance at Dec. 31, 2018	$ 371	343,955	(4,531)	(361,023)	(696)	$ (21,924)
Balance (in shares) at Dec. 31, 2018	36,921,000					36,921,174
Increase (Decrease) in Stockholders' Equity
Net income (loss)	$ 0	0	0	27,525	0	$ 27,525
Share based compensation expense		13,414				13,414
Issuance of common stock upon vesting of restricted stock units | ASU 2018-02	$ 4	(4)
Issuance of common stock upon vesting of restricted stock units (in shares) | ASU 2018-02	435,000
Issuance of common stock upon vesting of restricted stock units (in shares)	0
Effect of shares withheld to cover taxes		(4,137)				(4,137)
Issuance of common stock in connection with the exercise of stock options	$ 1	1,098				1,099
Issuance in connection with the exercise of stock options (in shares)	104,000
Total other comprehensive (loss) income			(8,020)			(8,020)
Balance at Dec. 31, 2019	$ 376	$ 354,326	$ (12,551)	$ (331,951)	$ (696)	$ 9,504
Balance (in shares) at Dec. 31, 2019	37,460,000					37,460,052