Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income tax expense	$ 4.1	$ 3.8
Effective tax rate	24.10%	34.50%
2017 Tax Act transition tax, rate applied to cash	15.50%
2017 Tax Act transition tax, rate applied to earnings in excess of cash	8.00%