Fair Values of Outstanding Derivative Instruments (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Derivative Assets:
Derivative Assets	$ 178
Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Interest rate contract | Prepaid revenue share, expenses and other assets, current and non-current
Derivative Assets:
Derivative Assets	1
Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Foreign Exchange Contract | Prepaid revenue share, expenses and other assets, current and non-current
Derivative Assets:
Derivative Assets	177	337
Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Foreign Exchange Contract | Accrued Expenses and Other Current Liabilities
Derivative Liabilities:
Derivative Liabilities	7	6
Derivatives designated as hedging instruments
Derivative Assets:
Derivative Assets	165
Derivatives designated as hedging instruments | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Interest rate contract | Prepaid revenue share, expenses and other assets, current and non-current
Derivative Assets:
Derivative Assets	1
Derivatives designated as hedging instruments | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Foreign Exchange Contract | Prepaid revenue share, expenses and other assets, current and non-current
Derivative Assets:
Derivative Assets	164	333
Derivatives designated as hedging instruments | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Foreign Exchange Contract | Accrued Expenses and Other Current Liabilities
Derivative Liabilities:
Derivative Liabilities	3	5
Derivatives not designated as hedging instruments
Derivative Assets:
Derivative Assets	13
Derivatives not designated as hedging instruments | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Interest rate contract | Prepaid revenue share, expenses and other assets, current and non-current
Derivative Assets:
Derivative Assets	0
Derivatives not designated as hedging instruments | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Foreign Exchange Contract | Prepaid revenue share, expenses and other assets, current and non-current
Derivative Assets:
Derivative Assets	13	4
Derivatives not designated as hedging instruments | Fair value measurement at reporting date using Significant Other Observable Inputs (Level 2) | Foreign Exchange Contract | Accrued Expenses and Other Current Liabilities
Derivative Liabilities:
Derivative Liabilities	$ 4	$ 1