Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Tax benefit adjustment to the provisional income tax expense	$ 5.3
Unrecognized net operating loss carryforwards, foreign	7.1	$ 11.5	$ 5.4
Foreign jurisdictions income with tax holidays	107.1	124.1	89.7
Income Taxes [Line Items]
Valuation allowance for deferred tax assets	350.4	402.2
Net decrease in valuation allowance	51.8
Tax loss carryforwards	1,800.0
Tax loss carryforwards with no expiration date	1,500.0
Tax loss carryforwards with expiration date	292.1
Tax credit carryforwards	260.6
Deferred tax asset	445.5	555.4
Retained earnings	4,113.6	4,171.9
Unrecognized tax benefits	36.7	33.2	29.5	$ 30.4
Unrecognized tax benefits, interest and penalties	11.8	9.9
Decrease in unrecognized tax benefits, reasonably possible during the next twelve months	4.2
U.S.
Income Taxes [Line Items]
Valuation allowance for deferred tax assets	16.0
International jurisdictions
Income Taxes [Line Items]
Valuation allowance for deferred tax assets	$ 334.4
Accounting Standards Update 2016-16
Income Taxes [Line Items]
Deferred tax asset		2.3
Retained earnings		$ 2.3
Accounting Standards Update 2016-09
Income Taxes [Line Items]
Deferred tax asset			52.9
Retained earnings			$ 52.9