Goodwill and Other Intangible Assets - Changes in Goodwill and Other Intangible Assets (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)
Goodwill and Other Intangible Assets [Roll Forward]
Amortizing Intangible Assets, Beginning Balance	$ 636
Finite-lived Intangible Assets Acquired	0
Amortizing Intangible Assets, Amortization expense	(67)
Finite-Lived Intangible Assets, Period Increase (Decrease)	(152)
Amortizing Intangible Assets, Ending Balance	417
Goodwill, Beginning Balance	2,366
Goodwill, Acquired During Period	3
Goodwill, Period Increase (Decrease)	(673)
Goodwill, Ending Balance	1,696
Other Non-Amortizing Intangible Assets, Beginning Balance	2,514
Indefinite-lived Intangible Assets Acquired	0
Indefinite-lived Intangible Assets, Period Increase (Decrease)	(2,366)
Other Non-Amortizing Intangible Assets, Ending Balance	$ 148