Quarterly Financial Results and Market for Company's Stock (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015
Income Statement [Abstract]
Business optimization, acquisition, collaboration arrangements and other benefits			$ 1,000	$ 3,100			$ 5
Business optimization, acquisition, collaboration arrangements and other charges	$ 47	$ 155			$ 17	$ 191		$ 29