Income Taxes - Narrative (Detail) - USD ($)		12 Months Ended
	Dec. 22, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Tax Credit Carryforward [Line Items]
Impact of Tax Cuts and Jobs Act		$ (53,100,000)	$ 0	$ 0
Unrecognized tax benefit		27,700,000	17,200,000	12,300,000
Increase in net income from recognition of unrecognized tax benefits		21,700,000	11,900,000
Increases in unrecognized tax benefits		10,500,000	4,900,000
Interest and penalties, net of tax, included in the provision (benefit) for income taxes		100,000	1,600,000
Liability for the potential payment of interest and penalties		10,300,000	9,900,000
Earnings of certain non-U.S. subsidiaries indefinitely reinvested		246,100,000	237,100,000	257,400,000
Approximated cumulative amount of undistributed pre-tax earnings in subsidiaries		1,900,000,000
Repatriation tax	$ 150,000,000
Valuation allowance		1,100,000	900,000	1,600,000
State
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards		1,100,000	900,000	1,600,000
Valuation allowance		0	$ 0	$ 0
Tax Year 2013 through 2016 | Federal
Tax Credit Carryforward [Line Items]
Tax Adjustments, Settlements, and Unusual Provisions		20,900,000
Tax Year 2013 through 2016 | State
Tax Credit Carryforward [Line Items]
Tax Adjustments, Settlements, and Unusual Provisions		$ (17,600,000)