CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands	Total	Common Stock Issued [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive (Loss) Income [Member]
Beginning Balance at Dec. 31, 2011		$ 2,547	$ (52,075)	$ 1,543,167	$ (16,377)	$ (542)
Beginning Balance, Shares at Dec. 31, 2011		254,691	(63,951)
Stock-based compensation				39,985
Common stock issued under stock compensation plans, net of shares withheld for employee taxes, Shares		2,396
Common stock issued under stock compensation plans, net of shares withheld for employee taxes		24		(4,797)
Purchases of treasury stock, Shares	(21,000)		(20,721)
Purchases of treasury stock	(225,961)		(225,961)
Excess tax benefit (deficiency) realized upon exercise of stock-based compensation				(1,095)
Net loss	(1,153)				(1,153)
Foreign currency translation adjustments, net	407					407
Unrecognized gain on interest rate swap, net of tax	133					133
Unrealized gain on marketable securities, net of tax	78					78
Ending Balance at Dec. 31, 2012	1,284,341	2,571	(278,036)	1,577,260	(17,530)	76
Ending Balance, Shares at Dec. 31, 2012		257,087	(84,672)
Stock-based compensation				36,252
Common stock issued under stock compensation plans, net of shares withheld for employee taxes, Shares		2,564
Issuance of common stock for acquisition of dbMotion, Shares		3,823
Common stock issued under stock compensation plans, net of shares withheld for employee taxes		26		2,479
Issuance of common stock for acquisition of dbMotion		38		48,023
Purchases of treasury stock, Shares	0
Excess tax benefit (deficiency) realized upon exercise of stock-based compensation				335
Warrants issued				52,498
Net loss	(104,026)				(104,026)
Foreign currency translation adjustments, net	(2,482)					(2,482)
Unrecognized gain on interest rate swap, net of tax	655					655
Unrealized gain on marketable securities, net of tax	6					6
Ending Balance at Dec. 31, 2013	1,318,145	2,635	(278,036)	1,716,847	(121,556)	(1,745)
Ending Balance, Shares at Dec. 31, 2013		263,474	(84,672)
Stock-based compensation				37,295
Common stock issued under stock compensation plans, net of shares withheld for employee taxes, Shares		1,664
Common stock issued under stock compensation plans, net of shares withheld for employee taxes		16		(6,969)
Purchases of treasury stock, Shares	0
Excess tax benefit (deficiency) realized upon exercise of stock-based compensation				(123)
Warrants issued				2,543
Net loss	(66,453)				(66,453)
Foreign currency translation adjustments, net	(529)					(529)
Unrecognized gain on interest rate swap, net of tax	279					279
Unrealized gain on marketable securities, net of tax	16					16
Ending Balance at Dec. 31, 2014	$ 1,284,220	$ 2,651	$ (278,036)	$ 1,749,593	$ (188,009)	$ (1,979)
Ending Balance, Shares at Dec. 31, 2014		265,138	(84,672)