Businesses Held for Sale and Discontinued Operations (Rollforward of the Reserve) (Details) - WMC - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Financial Information For Discontinued Operations [Line Items]
Reserve, beginning of period	$ 833	$ 814	$ 875	$ 809	$ 809
Provision	27	11	84	18
Claim resolutions	0	0	(99)	(2)
Reserve, end of period	860	$ 825	860	$ 825	875
Pending claims, beginning of period			2,887
New claims			7,266		8,047
Pending claims, end of period	2,688		2,688		$ 2,887
Claims Relating To Alleged Breaches Of Representations That Are Beyond Applicable Statute Of Llimitations	$ 110		$ 110