Fair Value Measurements (Aggregate Fair Value of Derivative Financial Instruments and Debt) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014
Fair Value [Member]
Assets:
Foreign exchange contracts	$ 101
Total assets	101
Liabilities:
Debt	27,684
Foreign exchange contracts	92
Total liabilities	27,776
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Assets:
Foreign exchange contracts	0
Total assets	0
Liabilities:
Debt	27,498
Foreign exchange contracts	0
Total liabilities	27,498
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Foreign exchange contracts	101
Total assets	101
Liabilities:
Debt	186
Foreign exchange contracts	92
Total liabilities	278
Significant Unobservable Inputs (Level 3) [Member]
Assets:
Foreign exchange contracts	0
Total assets	0
Liabilities:
Debt	0
Foreign exchange contracts	0
Total liabilities	$ 0