Restructuring and Other Charges - Activity and Reserve Balances for Restructuring Charges (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring reserve beginning balance	$ 59	$ 93
Cash payments	(22)	(86)
Restructuring charges	20	97
Other	(3)	(45)
Restructuring reserve ending balance	54	59
Layoff Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve beginning balance	50	84
Cash payments	(18)	(73)
Restructuring charges	20	70
Other	(2)	(31)
Restructuring reserve ending balance	50	50
Other Exit Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve beginning balance	9	9
Cash payments	(4)	(13)
Restructuring charges		27
Other	(1)	(14)
Restructuring reserve ending balance	$ 4	$ 9