Financial Instruments - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Financial Instruments and Fair Value [Line Items]
Gross realized gains on the sale of our marketable securities	$ 383,000,000	$ 381,000,000
Gross realized losses on the sale of our marketable securities	101,000,000	127,000,000
Other-than-temporary impairment charge on investment	0	110,000,000	0
Cash collateral received from derivative financial instruments	43,000,000	113,000,000
Forward-starting interest swaps, notional amount	1,000,000,000
Forward-starting interest swaps, anticipated debt issuance amount	1,000,000,000
Effective portion of our cash flow hedges before tax effect	11,000,000
Cash flow hedges, expected to be reclassified from AOCI to revenues within the next 12 months	10,000,000
Total notional amounts of interest rate contracts	25,000,000	100,000,000
Derivatives not designated as hedging instruments
Financial Instruments and Fair Value [Line Items]
Notional principal of foreign exchange contracts outstanding	6,600,000,000	3,700,000,000
Cash Flow Hedging Relationship | Foreign exchange contracts to purchase U.S. dollars with foreign currencies
Financial Instruments and Fair Value [Line Items]
Notional principal of foreign exchange contracts	9,500,000,000	6,500,000,000
Cash Flow Hedging Relationship | Foreign exchange contracts to purchase US dollars
Financial Instruments and Fair Value [Line Items]
Foreign exchange option contracts, maximum maturities (in months)	36 months
Derivatives in Fair Value Hedging Relationship | Foreign exchange contracts to purchase U.S. dollars with foreign currencies
Financial Instruments and Fair Value [Line Items]
Notional principal of foreign exchange contracts	1,100,000,000	1,000,000,000
Clearwire Corporation
Financial Instruments and Fair Value [Line Items]
Other-than-temporary impairment charge on investment		$ 88,000,000