Consolidated Statements of Stockholders' Equity and Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Retained Earnings (Accumulated Deficit)	Comprehensive Income (Loss)
Balances at Dec. 31, 2008	$ 802,084	$ 449	$ 1,238,796	$ 113,999	$ (551,160)
Balances (in shares) at Dec. 31, 2008		448,872
Comprehensive income (loss):
Net income (loss)	(109,498)				(109,498)	(109,498)
Actuarial gain (loss) related to defined benefit pension plans	413			413		413
Unrealized gains (losses) on investments, net of tax	327			327		327
Foreign currency translation adjustments	25,731			25,731		25,731
Total comprehensive income (loss)	(83,027)					(83,027)
Stock-based compensation expense	37,730		37,730
Exercise of stock options	3,263	1	3,262
Exercise of stock options (in shares)		1,206
Issuance of common stock under employee stock purchase plan	6,483	2	6,481
Issuance of common stock under employee stock purchase plan (in shares)		2,139
Common stock issued in lieu of 2008 bonus awards	1,945	1	1,944
Common stock issued in lieu of 2008 bonus awards (in shares)		632
Vested restricted stock units	3	3
Vested restricted stock units (in shares)		3,014
Shares withheld for employee taxes related to vested restricted stock units	(4,074)	(1)	(4,073)
Shares withheld for employee taxes related to vested restricted stock units		(1,277)
Balances at Dec. 31, 2009	764,407	455	1,284,140	140,470	(660,658)
Balances (in shares) at Dec. 31, 2009		454,586
Comprehensive income (loss):
Net income (loss)	423,075				423,075	423,075
Actuarial gain (loss) related to defined benefit pension plans	(788)			(788)		(788)
Unrealized gains (losses) on investments, net of tax	(2,102)			(2,102)		(2,102)
Recognition of cumulative foreign CTA adjustments (See Note 10)	(99,779)			(99,779)		(99,779)
Foreign currency translation adjustments	(21,472)			(21,472)		(21,472)
Total comprehensive income (loss)	298,934					298,934
Stock-based compensation expense	58,487		58,487
Tax benefit on stock-based compensation expense	1,664		1,664
Exercise of stock options	22,498	5	22,493
Exercise of stock options (in shares)		5,344
Issuance of common stock under employee stock purchase plan	7,413	2	7,411
Issuance of common stock under employee stock purchase plan (in shares)		2,028
Vested restricted stock units	5	5
Vested restricted stock units (in shares)		4,816
Shares withheld for employee taxes related to vested restricted stock units	(11,139)	(1)	(11,138)
Shares withheld for employee taxes related to vested restricted stock units		(1,418)
Common stock issued to former employees of Quantum (See Note 3)	3	3
Common stock issued to former employees of Quantum (See Note 3) (in shares)		3,152
Repurchase of common stock	(89,216)	(12)	(89,204)
Repurchase of common stock (in shares)	(11,720)	(11,720)
Balances at Dec. 31, 2010	1,053,056	457	1,273,853	16,329	(237,583)
Balances (in shares) at Dec. 31, 2010		456,788
Comprehensive income (loss):
Net income (loss)	314,990				314,990	314,990
Actuarial gain (loss) related to defined benefit pension plans	(197)			(197)		(197)
Unrealized gains (losses) on investments, net of tax	179			179		179
Foreign currency translation adjustments	(6,863)			(6,863)		(6,863)
Total comprehensive income (loss)	308,109					308,109
Stock-based compensation expense	69,102		69,102
Tax benefit on stock-based compensation expense	939		939
Exercise of stock options	19,340	4	19,336
Exercise of stock options (in shares)		4,285
Issuance of common stock under employee stock purchase plan	9,406	2	9,404
Issuance of common stock under employee stock purchase plan (in shares)		1,514
Vested restricted stock units	6	6
Vested restricted stock units (in shares)		6,345
Vested performance-based restricted stock units	8	8
Vested performance-based restricted stock units (in shares)		8,485
Shares withheld for employee taxes related to vested restricted stock units	(73,286)	(6)	(73,280)
Shares withheld for employee taxes related to vested restricted stock units		(6,252)
Repurchase of common stock	(304,236)	(29)	(304,207)
Repurchase of common stock (in shares)	(28,776)	(28,776)
Balances at Dec. 31, 2011	$ 1,082,444	$ 442	$ 995,147	$ 9,448	$ 77,407
Balances (in shares) at Dec. 31, 2011		442,389