Goodwill and Identifiable Intangible Assets - Summarize of Identifiable Intangible Assets with Definite and Indefinite Useful Lives (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2012
Finite And Infinite Lived Intangible Assets [Line Items]
Pre-tax impairment charge of indefinite lived intangible assets	$ 189
In Process Research and Development [Member]
Finite And Infinite Lived Intangible Assets [Line Items]
Impairment recorded		22
Impairment recorded, net of taxes		14
Trademarks and trade names [Member]
Finite And Infinite Lived Intangible Assets [Line Items]
Pre-tax impairment charge of indefinite lived intangible assets	$ 189	$ 441