Goodwill and Other Intangible Assets - Changes in Goodwill and Other Intangible Assets (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($)
Goodwill and Other Intangible Assets [Roll Forward]
Amortizing Intangible Assets, Beginning Balance	$ 285
Amortizing Intangible Assets, Amortization expense	(16)
Amortizing Intangible Assets, Ending Balance	269
Goodwill, Beginning Balance	1,608
Goodwill, Ending Balance	1,608
Other Non-Amortizing Intangible Assets, Beginning Balance	148
Other Non-Amortizing Intangible Assets, Ending Balance	$ 148