Goodwill and Other Intangible Assets - Estimated Aggregate Pre-Tax Amortization Expense Related to Intangible Assets (Details) $ in Millions	Sep. 30, 2015 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense remainder of 2015	$ 2
Amortization expense 2016	8
Amortization expense 2017	5
Amortization expense 2018	2
Amortization expense 2019	$ 1