Derivative Financial Instruments and Risk Management (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivatives, Fair Value
Asset Fair Value	$ 101	$ 138	$ 238
Liability Fair Value	(23)	(10)	(15)
Designated derivatives
Derivatives, Fair Value
Asset (Liability) Fair Value	71	116	218
Designated derivatives | Interest rate contracts | Other assets
Derivatives, Fair Value
Asset Fair Value	79	122	226
Designated derivatives | Interest rate contracts | Accrued expenses
Derivatives, Fair Value
Liability Fair Value	(8)	(6)	(8)
Undesignated derivatives
Derivatives, Fair Value
Asset (Liability) Fair Value	7	12	5
Undesignated derivatives | Interest rate contracts | Other assets
Derivatives, Fair Value
Asset Fair Value	0	0	2
Undesignated derivatives | Interest rate contracts | Accrued expenses
Derivatives, Fair Value
Liability Fair Value	0	0	(1)
Undesignated derivatives | Foreign exchange contracts | Other assets
Derivatives, Fair Value
Asset Fair Value	5	7	10
Undesignated derivatives | Foreign exchange contracts | Accrued expenses
Derivatives, Fair Value
Liability Fair Value	(15)	(4)	(5)
Undesignated derivatives | Cross currency contracts | Other assets
Derivatives, Fair Value
Asset Fair Value	17	9	0
Undesignated derivatives | Cross currency contracts | Accrued expenses
Derivatives, Fair Value
Liability Fair Value	$ 0	$ 0	$ (1)