Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Equity securities	$ 15	$ 21
Contingent payments related to acquisitions and investments, liabilities at fair value	86
Fair Value, Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Foreign currency hedges, assets at fair value	75	55
Interest rate hedges, assets at fair value	67	77
Equity securities	15	21
Total assets	224	153
Foreign currency hedges, liabilities at fair value	16	4
Interest rate hedges, liabilities at fair value	21	11
Contingent payments related to acquisitions and investments, liabilities at fair value	86	234
Total liabilities	123	249
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Equity securities	15	21
Total assets	15	21
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Foreign currency hedges, assets at fair value	75	55
Interest rate hedges, assets at fair value	67	77
Total assets	158	132
Foreign currency hedges, liabilities at fair value	16	4
Interest rate hedges, liabilities at fair value	21	11
Total liabilities	37	15
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Total assets	51
Contingent payments related to acquisitions and investments, liabilities at fair value	86	234
Total liabilities	86	234
Fair Value, Measurements, Recurring | Preferred Stock
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Debt securities	51
Fair Value, Measurements, Recurring | Preferred Stock | Fair Value, Inputs, Level 3
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Debt securities	51
Fair Value, Measurements, Recurring | Foreign Government Debt Securities
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Debt securities	16
Fair Value, Measurements, Recurring | Foreign Government Debt Securities | Fair Value, Inputs, Level 2
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Debt securities	$ 16