Fair Value Hierarchy For Financial Assets And Liabilities Measured At Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	$ 10,906,078
Convertible debt	(2,702,220)
Foreign exchange derivative assets	26,955
Foreign exchange derivative liabilities	(35,865)
Cash
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	1,662,937
Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	2,330,081
US Government Agencies Debt Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	2,309,437
US Corporate Debt Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	1,506,607
High Yield Corporate Debt Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	462,387
Asset-backed Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	39,972
Municipal Obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	1,219,078
Auction Rate Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	73,896
Foreign Debt Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	1,197,928
Publicly Traded Equity Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	103,755
Strategic Investments Held At Cost
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	204,963
Commodity Contract
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative liabilities	(3,371)
Interest Rate Swap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative liabilities	(30,207)
Fair Value, Inputs, Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	5,367,486
Fair Value, Inputs, Level 1 | Cash
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	1,662,937
Fair Value, Inputs, Level 1 | Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	2,265,587
Fair Value, Inputs, Level 1 | US Government Agencies Debt Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	1,335,207
Fair Value, Inputs, Level 1 | Publicly Traded Equity Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	103,755
Fair Value, Inputs, Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	5,464,696
Convertible debt	(2,702,220)
Foreign exchange derivative assets	26,955
Foreign exchange derivative liabilities	(35,865)
Fair Value, Inputs, Level 2 | Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	64,494
Fair Value, Inputs, Level 2 | US Government Agencies Debt Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	974,230
Fair Value, Inputs, Level 2 | US Corporate Debt Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	1,506,607
Fair Value, Inputs, Level 2 | High Yield Corporate Debt Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	462,387
Fair Value, Inputs, Level 2 | Asset-backed Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	39,972
Fair Value, Inputs, Level 2 | Municipal Obligations
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	1,219,078
Fair Value, Inputs, Level 2 | Foreign Debt Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	1,197,928
Fair Value, Inputs, Level 2 | Commodity Contract
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative liabilities	(3,371)
Fair Value, Inputs, Level 2 | Interest Rate Swap
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Commodity derivative liabilities	(30,207)
Fair Value, Inputs, Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	73,896
Fair Value, Inputs, Level 3 | Auction Rate Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	73,896
Fair Value, Inputs, Level 3 | Strategic Investments Held At Cost
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash and investments	$ 204,963