Capital Structure - Additional Information (Detail) - Common Stock [Member] - USD ($)	1 Months Ended	9 Months Ended
	May 31, 2016	Sep. 30, 2016	Oct. 26, 2015
Capital Structure [Line Items]
Repurchase of common stock, shares		(29,064,000)
Repurchase price of common stock, per share		$ 76.16
Share repurchase program authorized amount			$ 3,000,000,000
Share repurchase program, remaining authorized repurchase amount		$ 390,000,000
Share Repurchase Program Two [Member]
Capital Structure [Line Items]
Repurchase of common stock, shares		(19,703,000)
Repurchase price of common stock, per share		$ 74.28
Kohlberg Kravis Roberts & Co [Member] | Share Repurchase Program One [Member]
Capital Structure [Line Items]
Repurchase of common stock, shares	(9,361,000)
Repurchase price of common stock, per share	$ 80.12
Percentage of discount on share repurchase	1.00%