Income Taxes (Details) (USD $)	3 Months Ended								9 Months Ended		12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Components of income before provision for income taxes and noncontrolling interest:
Domestic											$ 218,400,000	$ 370,600,000	$ 50,100,000
Foreign											353,300,000	407,600,000	262,000,000
Income before income taxes and noncontrolling interest	122,500,000	121,100,000	157,200,000	170,900,000	231,600,000	195,700,000	189,000,000	161,700,000			571,716,000	778,154,000	312,061,000
Current (benefit) provision:
Federal											19,500,000	(8,400,000)	123,800,000
State											900,000	1,000,000	21,400,000
Foreign											47,800,000	44,200,000	43,500,000
Total current provision											68,200,000	36,800,000	188,700,000
Deferred expense (benefit):
Federal											23,000,000	57,500,000	(42,700,000)
State											600,000	14,000,000	55,700,000
Foreign											(3,600,000)	(7,500,000)	(5,900,000)
Total deferred expense											20,000,000	64,000,000	7,100,000
Income tax benefits attributable to employee stock plan activity												(73,400,000)
Income tax provision	26,300,000	37,400,000	41,700,000	41,300,000	41,500,000	61,400,000	58,700,000	(2,900,000)			146,704,000	158,781,000	196,833,000
Provision for income taxes, Income tax reconciliation
Expected provision at 35% rate											200,100,000	272,400,000	109,200,000
State taxes, net of federal benefit											2,000,000	6,200,000	(1,600,000)
Foreign income at different tax rates											(50,400,000)	(71,500,000)	(33,800,000)
R&D credits											(21,300,000)	(18,600,000)	(14,400,000)
Stock-based compensation											16,700,000	(40,200,000)	62,100,000
Temporary differences not currently benefited											0	10,200,000	72,800,000
Other											(400,000)	300,000	2,500,000
Income Tax Expense (Benefit)	26,300,000	37,400,000	41,700,000	41,300,000	41,500,000	61,400,000	58,700,000	(2,900,000)			146,704,000	158,781,000	196,833,000
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Federal statutory rate		35.00%				35.00%			35.00%	35.00%
Deferred tax assets:
Net operating loss carry-forwards	4,400,000				14,100,000						4,400,000	14,100,000
Foreign tax credit carry-forwards	48,700,000				40,300,000						48,700,000	40,300,000
Research and other credit carry-forwards	86,300,000				68,200,000						86,300,000	68,200,000
Deferred revenue	94,000,000				86,100,000						94,000,000	86,100,000
Stock-based compensation	91,200,000				75,600,000						91,200,000	75,600,000
Reserves and accruals not currently deductible	255,900,000				227,600,000						255,900,000	227,600,000
Other	31,000,000				26,800,000						31,000,000	26,800,000
Total deferred tax assets	611,500,000				538,700,000						611,500,000	538,700,000
Valuation allowance	(145,200,000)				(122,200,000)						(145,200,000)	(122,200,000)
Deferred tax assets, net of valuation allowance	466,300,000				416,500,000						466,300,000	416,500,000
Deferred tax liabilities:
Property and equipment basis differences	(87,000,000)				(47,100,000)						(87,000,000)	(47,100,000)
Purchased intangibles	(53,200,000)				(58,500,000)						(53,200,000)	(58,500,000)
Unremitted foreign earnings	(210,500,000)				(175,100,000)						(210,500,000)	(175,100,000)
Other	0				(100,000)						0	(100,000)
Total deferred tax liabilities	(350,700,000)				(280,800,000)						(350,700,000)	(280,800,000)
Deferred Tax Assets (Liabilities), Net	115,600,000				135,700,000						115,600,000	135,700,000
Valuation Allowances and Reserves, Period Increase (Decrease)											23,000,000	9,400,000
Operating Loss Carryforwards	9,600,000				39,600,000						9,600,000	39,600,000
Indefinitely Invested Undistributed Earnings											1,462,600,000
Estimated Deferred Tax Liability Cumulative Indefinitely Invested Undistributed Earnings											447,300,000
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized Tax Benefits				116,400,000				183,600,000	116,400,000	183,600,000	116,400,000	183,600,000	113,500,000
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions											17,600,000	13,900,000	12,700,000
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions											6,400,000	0	73,500,000
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions											0	(73,800,000)	(1,000,000)
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities											(5,400,000)	(1,600,000)	(12,800,000)
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations											(2,800,000)	(5,700,000)	(2,300,000)
Unrecognized Tax Benefits	132,200,000				116,400,000						132,200,000	116,400,000	183,600,000
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued													14,800,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	117,200,000										117,200,000
Possible decrease in gross unrecognized tax benefits within next 12 months		3,500,000							3,500,000
Income Tax Reconciliation, Tax Settlements, State and Local											7,000,000
Income tax benefits attributable to employee stock plan activity											(58,500,000)	(58,000,000)	(1,000,000)
California [Member]
Deferred tax liabilities:
Tax Credit Carryforward, Amount	159,800,000										159,800,000
Tax Credit Carryforward, Amount, Credit to APIC	21,300,000										21,300,000
Foreign Country [Member]
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Interest and penalties recorded	4,600,000										4,600,000
California Deferred Tax Assets [Member]
Deferred tax assets:
Valuation allowance	(94,300,000)										(94,300,000)
Massachusetts Deferred Tax Assets [Member]
Deferred tax assets:
Valuation allowance	(9,700,000)										(9,700,000)
Capital Loss Carry Forward [Member]
Deferred tax assets:
Valuation allowance	(41,200,000)										(41,200,000)
Other Long Term Liabilities [Member]
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	17,300,000				18,900,000						17,300,000	18,900,000	23,500,000
Consolidated Statement Of Operation [Member]
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ (1,600,000)				$ (4,600,000)						$ (1,600,000)	$ (4,600,000)