Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other Income Tax Expense [Line Items]
Effective income tax rate	19.00%	22.40%	20.00%	14.80%
Release of valuation allowances			$ 9.8
Excess tax benefits	$ 0.6		4.7
Foreign rate changes
Other Income Tax Expense [Line Items]
Other tax expense			13.1
Out-of-period adjustments
Other Income Tax Expense [Line Items]
Other tax expense			$ 5.1