Acquisition of Trade King Acquisition of Trade King (Details) - USD ($)	Jun. 30, 2016	Jun. 01, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Business Acquisition Cash Paid		$ 298,000,000
Business Acquisition, Goodwill, Expected Tax Deductible Amount		0
Goodwill	$ 220,000,000		$ 27,000,000
Other Intangible Assets [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest		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, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest		14,000,000
Deferred Tax Asset [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest		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	$ 0