Income Taxes - Continuing Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Provision for income taxes	$ (93)	$ 11	$ 49	$ 104	$ (19)	$ (12)	$ 351	$ 18	$ 71	$ 338	$ 227
Income taxes related to adjustments included in common shareholder’s equity:
Unrealized gains (losses) on securities available-for-sale, net									(697)	76	552
Unrealized gains (losses) on derivatives classified as cash flow hedges									82	17	(110)
Employer accounting for post-retirement plans									6	5	(3)
Other-than-temporary impairment on debt securities									(43)	0	1
Total									$ (581)	$ 436	$ 667