Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Statutory federal income tax rate			21.00%	35.00%	35.00%
GILTI			11.60%	0.00%	0.00%
Provisional net reduction in deferred tax liabilities	$ 35.0		$ 7.3	$ 35.0
Net operating loss carryforwards during period	43.0		43.0
Foreign net operating loss carryforwards	16.1		16.1
Indefinite operating loss carryforwards			26.9
State tax net operating loss carryforwards	8.4		8.4
Deferred tax assets, tax credit carryforwards, foreign		$ 26.6		26.6
Transition tax foreign credits				43.5
Deferred tax assets, valuation allowance	23.7	25.7	23.7	25.7
Provisional net benefit recorded to income tax expense			2.3	30.9
Deferred Other Tax Expense (Benefit)			5.0	53.9
Additional provisional tax benefit		6.3	5.6
Foreign subsidiaries undistributed earnings	216.5		216.5
Foreign Earnings Repatriated			125.4
Gross unrecognized tax benefits	2.9	3.8	2.9	3.8	$ 2.8	$ 1.5
Effective tax rate impact if ultimately recognized	2.9	3.8	2.9	3.8
Amount accrued for interest and penalties	0.3	$ 0.2	0.3	$ 0.2
Interest and penalties related to unrecognized tax benefits					$ 0.1
Expected change in unrecognized tax benefits			1.5
Gross unrecognized tax benefits may be recognized within the next twelve months	$ 0.5		$ 0.5