Goodwill and Other Intangible Assets - Identifiable Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 31,924
Finite-Lived Intangible Assets, Accumulated Amortization	5,016
Finite-Lived Intangible Assets [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	8,393
Finite-Lived Intangible Assets, Accumulated Amortization	5,016
Indefinite-lived Intangible Assets [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 23,531