Income Taxes - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Tax Credit Carryforward [Line Items]
Provision for income taxes	$ 418,300,000	$ 451,900,000	$ 401,400,000
Effective income tax rate reconciliation, percent	25.70%	23.20%	20.50%
Effective income tax rate reconciliation, prior year income taxes, amount	$ 26,800,000
Unrecognized tax benefit	22,400,000	$ 25,300,000	$ 21,900,000	$ 27,700,000
Increase in net income from recognition of unrecognized tax benefits	20,700,000	22,700,000
Interest and penalties, net of tax, included in the provision (benefit) for income taxes	1,200,000	1,300,000	$ 300,000
Income tax examination, penalties and interest accrued	9,600,000	8,400,000
Valuation allowance	55,200,000	29,800,000
State and Local Jurisdiction
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	500,000	1,000,000.0
Valuation allowance	500,000	300,000
Foreign Tax Authority
Tax Credit Carryforward [Line Items]
Valuation allowance	$ 25,300,000	$ 29,500,000