Capital Stock and Earnings per Share - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Preferred stock, shares authorized	250,000,000
Preferred stock, shares issued	0
Preferred stock, shares outstanding	0
Options to purchase shares of common stock not included in the computation of diluted earnings per share	500,000		3,100,000
Repurchased shares of common stock	1,400,000
Average price per share	$ 106.01
Total cash outlay	$ 150.0	$ 400.5	$ 719.0