Income Taxes - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefit that Would Not Impact Effective Tax Rate, Tax Position with Uncertain Timing of Deductibility	$ 6.2		$ 4.6
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	0.5		$ 0.5
Income Taxes Paid, Net	$ 5.5	$ 10.4