Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Income Tax Contingency [Line Items]
Tax year subject to tax examination for U.S. Federal return		As of March 31, 2018, we are no longer subject to examination by U.S. federal tax authorities for years prior to 2014, to examination for any U.S. state taxing authority prior to 2012, or to examination for any foreign jurisdictions prior to 2013. All subsequent periods remain open to examination.
Effective income tax rate, percent		25.00%	34.40%
U.S federal tax rate		21.00%		35.00%
Provisional income tax expense related to repatriation of foreign earnings	$ 3.1	$ 0.0
Unrecognized excess tax benefits		$ 14.1
Minimum
Income Tax Contingency [Line Items]
Step two threshold to quantify uncertain tax position		50.00%