Goodwill and Other Intangible Assets - Identifiable Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 36,805
Finite-Lived Intangible Assets, Accumulated Amortization	5,066
INTANGIBLE ASSETS WITH DETERMINABLE LIVES
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	9,955
Finite-Lived Intangible Assets, Accumulated Amortization	5,066
INTANGIBLE ASSETS WITH INDEFINITE LIVES
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 26,850