Acquisitions/Dispositions Schedule of Business Acquisitions, by Acquisition (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 15, 2016
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		$ (197)
Proceeds from Divestiture of Businesses		0	$ 0	$ 193
Goodwill, Written off Related to Sale of Business Unit				0
Intangible Assets, Written off Related to Sale of Business Unit				0
Gain (Loss) on Disposition of Business		0	$ 0	$ 105
Goodwill, Acquired During Period		0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	[1]				$ 14
Business Combination, Bargain Purchase, Gain Recognized, Amount		$ 0

[1] Does not include servicing rights acquired.