Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional paid-in capital	Treasury stock	Accumulated other comprehensive income (loss)	Accumulated deficit	Total
Beginning balance at Dec. 31, 2018	$ 3	$ 554,403	$ (35,706)	$ (52)	$ (451,961)	$ 66,687
Beginning balance (in shares) at Dec. 31, 2018	25,483
Issuance of stock under employee stock awards and other, net		270				270
Issuance of stock under employee stock awards and other, net (in shares)	319
Tax withholdings related to vesting of share-based payments		(1,322)				(1,322)
Stock-based compensation expense		2,045				2,045
Foreign currency translation adjustment				27		27
Net income (loss)					(10,286)	(10,286)
Ending balance at Mar. 31, 2019	$ 3	555,396	(35,706)	(25)	(462,247)	57,421
Ending balance (in shares) at Mar. 31, 2019	25,802
Beginning balance at Dec. 31, 2018	$ 3	554,403	(35,706)	(52)	(451,961)	66,687
Beginning balance (in shares) at Dec. 31, 2018	25,483
Foreign currency translation adjustment						3
Net income (loss)						(17,048)
Ending balance at Jun. 30, 2019	$ 3	557,185	(35,706)	(49)	(469,009)	52,424
Ending balance (in shares) at Jun. 30, 2019	25,989
Beginning balance at Mar. 31, 2019	$ 3	555,396	(35,706)	(25)	(462,247)	57,421
Beginning balance (in shares) at Mar. 31, 2019	25,802
Issuance of stock under employee stock awards and other, net		175				175
Issuance of stock under employee stock awards and other, net (in shares)	187
Tax withholdings related to vesting of share-based payments		(717)				(717)
Stock-based compensation expense		2,331				2,331
Foreign currency translation adjustment				(24)		(24)
Net income (loss)					(6,762)	(6,762)
Ending balance at Jun. 30, 2019	$ 3	557,185	(35,706)	(49)	(469,009)	52,424
Ending balance (in shares) at Jun. 30, 2019	25,989
Beginning balance at Dec. 31, 2019	$ 3	562,332	(35,706)	(20)	(478,799)	$ 47,810
Beginning balance (in shares) at Dec. 31, 2019	26,283					26,283
Issuance of stock under employee stock awards and other, net		6				$ 6
Issuance of stock under employee stock awards and other, net (in shares)	320
Tax withholdings related to vesting of share-based payments		(556)				(556)
Stock-based compensation expense		2,833				2,833
Foreign currency translation adjustment				(62)		(62)
Net income (loss)					(10,676)	(10,676)
Ending balance at Mar. 31, 2020	$ 3	564,615	(35,706)	(82)	(489,475)	39,355
Ending balance (in shares) at Mar. 31, 2020	26,603
Beginning balance at Dec. 31, 2019	$ 3	562,332	(35,706)	(20)	(478,799)	$ 47,810
Beginning balance (in shares) at Dec. 31, 2019	26,283					26,283
Foreign currency translation adjustment						$ (67)
Net income (loss)						(9,873)
Ending balance at Jun. 30, 2020	$ 3	567,126	(35,706)	(87)	(488,672)	$ 42,664
Ending balance (in shares) at Jun. 30, 2020	26,815					26,815
Beginning balance at Mar. 31, 2020	$ 3	564,615	(35,706)	(82)	(489,475)	$ 39,355
Beginning balance (in shares) at Mar. 31, 2020	26,603
Issuance of stock under employee stock awards and other, net		22				22
Issuance of stock under employee stock awards and other, net (in shares)	212
Tax withholdings related to vesting of share-based payments		(191)				(191)
Stock-based compensation expense		2,680				2,680
Foreign currency translation adjustment				(5)		(5)
Net income (loss)					803	803
Ending balance at Jun. 30, 2020	$ 3	$ 567,126	$ (35,706)	$ (87)	$ (488,672)	$ 42,664
Ending balance (in shares) at Jun. 30, 2020	26,815					26,815