Investment Securities (Investments, by type and length in continuous loss position) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	$ 1,226	$ 4,271
Gross unrealized losses, less than 12 months	(21)	(268)
Estimated fair value, 12 months or more	1,048	686
Gross unrealized losses, 12 months or more	(111)	(140)
US Corporate
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	229	2,966
Gross unrealized losses, less than 12 months	(9)	(218)
Estimated fair value, 12 months or more	689	433
Gross unrealized losses, 12 months or more	(42)	(67)
State and municipal
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	0	494
Gross unrealized losses, less than 12 months	0	(20)
Estimated fair value, 12 months or more	159	155
Gross unrealized losses, 12 months or more	(48)	(53)
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	53
Mortgage and asset-backed
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	250	719
Gross unrealized losses, less than 12 months	(6)	(20)
Estimated fair value, 12 months or more	168	84
Gross unrealized losses, 12 months or more	(17)	(16)
Corporate - non-U.S.
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	718	56
Gross unrealized losses, less than 12 months	0	(4)
Estimated fair value, 12 months or more	31	14
Gross unrealized losses, 12 months or more	(4)	(4)
Equity Securities
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	28	36
Gross unrealized losses, less than 12 months	(5)	(6)
Estimated fair value, 12 months or more	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	535
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	19
GE Capital | Equity Securities
Available-for-sale Securities Estimated Fair Value And Gross Unrealized Losses [Abstract]
Estimated fair value, less than 12 months	18	6
Gross unrealized losses, less than 12 months	$ (4)	$ (2)