CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Dec. 31, 2013	$ 494,166	$ 99	$ 2,336,275	$ (1,841,999)	$ (209)
Balance, Shares at Dec. 31, 2013		99,413
Net loss	(46,248)			(46,248)
Other comprehensive loss, net of tax	(1,771)				(1,771)
Issuance of Common Stock under option, stock award and purchase plans	1,106	$ 2	1,104
Issuance of Common Stock under option, stock award and purchase plans, Shares		2,181
Repurchase of Common Stock	(93,128)	$ (13)	(93,115)
Repurchase of Common Stock, Shares		(13,894)
Stock-based compensation	17,287		17,287
Excess tax benefits from stock-based compensation	401		401
Balance at Dec. 31, 2014	371,813	$ 88	2,261,952	(1,888,247)	(1,980)
Balance, Shares at Dec. 31, 2014		87,700
Net loss	(15,661)			(15,661)
Other comprehensive loss, net of tax	(2,438)				(2,438)
Issuance of Common Stock under option, stock award and purchase plans	5,673	$ 3	5,670
Issuance of Common Stock under option, stock award and purchase plans, Shares		2,855
Repurchase of Common Stock	(72,863)	$ (15)	(72,848)
Repurchase of Common Stock, Shares		(14,540)
Stock-based compensation	15,582		15,582
Conversion feature of convertible notes due 2020	26,062		26,062
Balance at Dec. 31, 2015	328,168	$ 76	2,236,418	(1,903,908)	(4,418)
Balance, Shares at Dec. 31, 2015		76,015
Net loss	(72,314)			(72,314)
Other comprehensive loss, net of tax	(2,852)				(2,852)
Issuance of Common Stock under option, stock award and purchase plans	2,800	$ 2	2,798
Issuance of Common Stock under option, stock award and purchase plans, Shares		2,441
Stock-based compensation	13,242		13,242
Issuance of warrant	1,597		1,597
Balance at Dec. 31, 2016	$ 270,641	$ 78	$ 2,254,055	$ (1,976,222)	$ (7,270)
Balance, Shares at Dec. 31, 2016		78,456