Equity (Detail) - USD ($)	1 Months Ended	3 Months Ended
	Jan. 31, 2016	Mar. 31, 2016	Mar. 31, 2015
Stockholders' Equity Note [Abstract]
Stock repurchase program, authorized amount		$ 1,200,000,000.0
Treasury stock, average price paid per share (in Dollars per share)		$ 82.02	$ 81.83
Purchases of treasury stock	$ 7,200,000	$ 45,487,000	$ 324,042,000