Acquisitions Acquisitions (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Aug. 01, 2016	Jun. 01, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross		$ 28,000,000	$ 298,000,000
Amortization of Intangible Assets	$ 6,000,000
Goodwill	240,000,000			$ 27,000,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount			0
Other Intangible Assets [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill			82,000,000
Cash and Cash Equivalents [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents			50,000,000
Other Assets [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill			14,000,000
Deferred Tax Asset [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill			4,000,000
Employee compensation and benefits [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents			40,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			(41,000,000)
Other Liabilities [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			(4,000,000)
Corporate and Other [Member]
Business Acquisition [Line Items]
Goodwill	193,000,000		$ 193,000,000	0
Automotive Finance Operations [Member]
Business Acquisition [Line Items]
Goodwill	$ 20,000,000	$ 20,000,000		$ 0