v3.8.0.1
Income Taxes Income Taxes - Components of Provision (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Abstract]      
Current Federal Tax Expense (Benefit) $ 0.0 $ 0.0 $ 0.0
Current Foreign Tax Expense (Benefit) 1.5 0.8 0.0
Current Income Tax Expense (Benefit) 1.6 0.9 0.1
Deferred Federal Income Tax Expense (Benefit) 0.0 (0.1) 0.0
Current State and Local Tax Expense (Benefit) 0.1 0.1 0.1
Deferred State and Local Income Tax Expense (Benefit) 0.0 0.0 0.0
Deferred Foreign Income Tax Expense (Benefit) 0.0 (0.1) 0.0
Deferred Income Tax Expense (Benefit) 0.0 (0.2) 0.0
Income taxes at effective rates $ 1.6 $ 0.7 $ 0.1