Investment Securities (Investments, by type and length in continuous loss position) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	$ 4,929		$ 4,929		$ 2,259
Gross unrealized losses, less than 12 months			(187)		(24)
Estimated fair value, 12 months or more	$ 560		560		1,554
Gross unrealized losses, 12 months or more			$ (116)		(136)
Percent of Gross unrealized losses, 12 months or more, considered investment grade	0.00%		0.00%
OTTI Previously Recognized Through OCI On Securities Held, Gross Unrealized Losses			$ 19
Incremental credit loss impairments recognized on securities previously impaired	$ 0	$ 1	0	$ 2
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, No Previous Impairment	14	0	14	0
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	0	$ 1	2	$ 53
US Corporate
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	2,267		2,267		554
Gross unrealized losses, less than 12 months			(113)		(16)
Estimated fair value, 12 months or more	246		246		836
Gross unrealized losses, 12 months or more			(34)		(53)
State and municipal
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	735		735		67
Gross unrealized losses, less than 12 months			(32)		(1)
Estimated fair value, 12 months or more	162		162		308
Gross unrealized losses, 12 months or more			(58)		(52)
Residential Mortgage Backed Securities
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	197		197		30
Gross unrealized losses, less than 12 months			(3)		0
Estimated fair value, 12 months or more	79		79		146
Gross unrealized losses, 12 months or more			(4)		(5)
Mortgage-backed Securities, Residential, Subprime, Financing Receivable [Member]
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Debt securities, Estimated fair value	63		63
Commercial mortgage backed
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	434		434		165
Gross unrealized losses, less than 12 months			(11)		(1)
Estimated fair value, 12 months or more	26		26		204
Gross unrealized losses, 12 months or more			(5)		(9)
Asset-backed
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	9		9		9
Gross unrealized losses, less than 12 months			0		0
Estimated fair value, 12 months or more	43		43		42
Gross unrealized losses, 12 months or more			(15)		(17)
Corporate - non-U.S.
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	36		36		42
Gross unrealized losses, less than 12 months			0		(1)
Estimated fair value, 12 months or more	3		3		3
Gross unrealized losses, 12 months or more			0		0
Government - non-U.S.
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	932		932		677
Gross unrealized losses, less than 12 months			(4)		(2)
Estimated fair value, 12 months or more	0		0		14
Gross unrealized losses, 12 months or more			0		0
U.S. Government and federal agency
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	278		278		705
Gross unrealized losses, less than 12 months			0		0
Estimated fair value, 12 months or more	1		1		1
Gross unrealized losses, 12 months or more			0		0
Retained interest
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	0		0		0
Gross unrealized losses, less than 12 months			0		0
Estimated fair value, 12 months or more	0		0		0
Gross unrealized losses, 12 months or more			0		0
Equity Securities
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	41		41		10
Gross unrealized losses, less than 12 months			(24)		(3)
Estimated fair value, 12 months or more	0		0		0
Gross unrealized losses, 12 months or more			0		0
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Debt securities, Estimated fair value	1,132		1,132
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Debt securities, Estimated fair value	26		26
GECC [Member] | Equity Securities
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	$ 29		29			$ 4
Gross unrealized losses, less than 12 months			$ (23)		$ (2)