Acquisitions/Dispositions Schedule of Business Acquisition, Purchase Price Allocation (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Dec. 15, 2016
Schedule of Business Acquisition, Purchase Price Allocation [Line Items]
Document Period End Date	Mar. 31, 2017
Business Combination, Consideration Transferred	$ 197	$ 197
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	9
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	13		$ 13
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other	8
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities	(100)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other	(16)
Goodwill, Acquired During Period	1
Loans Held For Investment [Member]
Schedule of Business Acquisition, Purchase Price Allocation [Line Items]
Business Combination, Acquired Receivables, Fair Value	38
Loans Held For Sale [Member]
Schedule of Business Acquisition, Purchase Price Allocation [Line Items]
Business Combination, Acquired Receivables, Fair Value	182
Commercial Mortgage Servicing Rights [Member]
Schedule of Business Acquisition, Purchase Price Allocation [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	62		$ 62
Pillar Financial [Member]
Schedule of Business Acquisition, Purchase Price Allocation [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	1
Net Assets	$ 196