XML 115 R101.htm IDEA: XBRL DOCUMENT v3.10.0.1
Income Taxes - Textual (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Valuation Allowance [Line Items]          
Tax Expense or Benefit Resulting from the Tax Cuts and Jobs Act $ 13.6        
Bonus Depreciation Deductions, Tax Cuts and Jobs Act 8.8        
Changes to valuation allowance during the period   $ 2.1 $ (7.9) $ (0.3)  
Remaining valuation allowance 35.8 33.7 35.8    
Estimated realization of additional tax benefits     51.3 0.1  
Unrecognized income tax benefits 0.3 0.9 0.3 2.8 $ 2.9
Unrecognized tax benefits, decrease     2.5    
Decrease in Unrecognized Tax Benefits is Reasonably Possible   0.5      
Unrecognized tax benefits that would have affected effective tax rate if recognized 0.3 0.9 $ 0.3 $ 2.8  
Federal [Member]          
Valuation Allowance [Line Items]          
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability 5.8        
State [Member]          
Valuation Allowance [Line Items]          
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability 13.8        
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount, Tax Cuts and Jobs Act $ 5.8        
Net operating loss   $ 66.0