Fair Value of Financial Instruments (Schedule of Pre-tax Gain (Loss) Recognized as a Component of Other Comprehensive Income) (Details) (Cash Flow Hedging [Member], Interest Rate Swap [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Cash Flow Hedging [Member] | Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Pre-Tax Gain (Loss) Recognized in OCI on Derivatives (Effective Portion)	$ (41)	$ (6)