Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Effective income tax rate (percent)		24.50%	37.00%
Gross unrecognized tax benefit	$ 5.6	$ 5.6		$ 5.2
Expected change in unrecognized tax benefits	1.3	1.3
Accrued interest on income taxes	1.5	1.5		1.1
Accrued penalties on income taxes, less than	0.1	$ 0.1		$ 0.1
Internal Revenue Service (IRS)
Income Tax Examination [Line Items]
Proceeds from income tax refunds	13.3
Interest income	$ 0.9