XML 64 R51.htm IDEA: XBRL DOCUMENT v3.7.0.1
Derivative Instruments - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Dec. 31, 2016
Nov. 01, 2016
Nov. 01, 2015
Derivative [Line Items]              
Gain on derivative $ 0.3            
Unrealized losses on derivatives     $ 6.7        
Derivative asset 0.9 $ 8.1 0.9 $ 8.1 $ 18.8    
Derivative liability 7.4 1.1 7.4 1.1 0.7    
Derivative, fair value $ 6.5 7.0 $ 6.5 7.0 $ 18.1    
Derivative, Loss on Derivative   $ 7.6   $ 23.1      
2016 - 2017              
Derivative [Line Items]              
Target hedge percentage, 2016 - 2017           75.00%  
2015 - 2016              
Derivative [Line Items]              
Target hedge percentage, 2016 - 2017             75.00%