Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended				3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Mar. 31, 2012 SandForce acquisition [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance related to tax benefits from stock option deductions	$ 102,000,000
Tax benefit related to valuation allowance release for SandForce acquisition	42,365,000				42,400,000
Net operating loss carryovers, federal	2,367,700,000
Net operating loss carryovers, state	1,416,500,000
Net operating loss carryovers, foreign	206,400,000
Federal net operating loss carryover related to acquisitions	2,163,200,000
State net operating loss carryover related to acquisitions	1,051,600,000
Tax credits	462,500,000
Income taxes paid, net of refunds received	21,000,000	11,800,000	29,300,000
Percentage reduction in tax rate on profits due to tax holiday	10.00%
Tax savings from income tax holiday	2,800,000	2,000,000	2,100,000
Cumulative undistributed earnings of various foreign subsidiaries	58,500,000
Unrecognized tax benefits that would impact effective tax rate	193,900,000	171,000,000
Unrecognized tax benefits	193,894,000	170,994,000	151,898,000	163,859,000
Estimated decrease in unrecognized tax benefits, plus accrued interest and penalties	22,200,000
Unrecognized tax benefits, income tax penalties and interest expense	8,300,000	6,300,000	7,700,000
Tax benefit on interest and penalties related to tax positions taken in a prior year, lapses in statutes of limitations and audit settlements	9,500,000	8,600,000	17,700,000
Income tax penalties and accrued interests	$ 28,400,000	$ 29,600,000