Income Taxes - Tax Reform (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Income Tax Disclosure [Abstract]
Income tax benefit	$ 9.9
Provisional impact related to remeasuring deferred taxes	31.0
Offsetting tax benefit of remeasured valuation allowance	31.0
Provisional reduction to NOLs	$ 102.6