Risk Management, Derivative Instruments And Hedging Activities (Cash Flow Hedges - Location And Amount Of Pre-Tax Recognized In Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Amount of pre-tax gains (losses) recorded in AOCI	$ (44)	$ (10)	$ (26)	$ (7)
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	(1)	(2)	(2)	(3)
Interest Rate Contracts [Member]
Amount of pre-tax gains (losses) recorded in AOCI	(44)	(10)	(26)	(7)
Total Pre-tax Gains and (Losses) Reclassified from AOCI into Earnings	$ (1)	$ (2)	$ (2)	$ (3)