Share Repurchase Programs and Dividends - Dividends (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Equity [Abstract]
Cash dividends declared (in dollars per share)	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0.30	$ 0.30
Cash paid	$ 53	$ 58	$ 61		$ 172