Equity - Additional Information (Detail) - USD ($)	2 Months Ended	12 Months Ended
	Feb. 19, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 04, 2014	Feb. 05, 2013
Class of Stock [Line Items]
Aggregate amount of repurchased shares		$ 740,000,000	$ 823,000,000	$ 800,000,000
Treasury Stock [Member]
Class of Stock [Line Items]
Aggregate amount of repurchased shares		$ 740,000,000	$ 823,000,000	$ 800,000,000
Share Repurchase Program February 5, 2013 [Member]
Class of Stock [Line Items]
Amount of shares authorized to be repurchased						$ 1,500,000,000
Average price per share of repurchased shares		$ 116.13
Aggregate amount of repurchased shares		$ 740,000,000
Share Repurchase Program February 5, 2013 [Member] | Treasury Stock [Member]
Class of Stock [Line Items]
Number of common shares repurchased		6,400,000
Share Repurchase Program December 4, 2014 [Member]
Class of Stock [Line Items]
Amount of shares authorized to be repurchased					$ 1,500,000,000
Remaining authorized amount of share repurchase programs		$ 806,000,000
Share Repurchase Program December 4, 2014 [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Average price per share of repurchased shares	$ 114.60
Aggregate amount of repurchased shares	$ 130,000,000
Remaining authorized amount of share repurchase programs	$ 676,000,000
Share Repurchase Program December 4, 2014 [Member] | Treasury Stock [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Number of common shares repurchased	1,133,885