v3.10.0.1
INCOME TAXES - Effective income tax rate on earnings (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2018
Dec. 31, 2017
Effect of:            
Effective income tax rate (as a percent)     (27.90%)      
Tax contingencies and other tax liabilities $ 18.1   $ 18.1     $ 15.3
Net deferred tax assets 14.8   14.8     $ 20.7
Income tax benefit $ (11.1) $ 17.6 $ (13.2) $ 136.4    
Forecast            
Effect of:            
Effective income tax rate (as a percent)         (3.40%)