Stockholders' Equity - Total Share-based Incentive Compensation Expense (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Total share-based incentive compensation expense	[1]	$ 16.8	$ 14.9	$ 31.2	$ 33.2

[1] The amounts included above do not include the expense related to our U.S. profit sharing contributions made in the form of our common stock or the expense or income related to SARs and certain cash-based awards. See Stock Appreciation Rights below for further details of SARs. At June 30, 2016 and June 30, 2015, our other cash-based awards were not material to our Condensed Consolidated Balance Sheet or Statement of Operations.