XML 44 R79.htm IDEA: XBRL DOCUMENT v3.19.3
Derivative Instruments and Hedging Activities - Pro Forma Impact Of Offsetting Assets (Details) - USD ($)
$ in Millions
Sep. 30, 2019
Dec. 31, 2018
Derivative Asset [Abstract]    
Gross asset $ 200.1 $ 149.4
Derivative assets 200.1 149.4
Pro forma net presentation, asset, total 143.7 116.4
Counterparties with Offsetting Positions or Collateral [Member]    
Derivative Asset [Abstract]    
Gross asset 151.0 108.9
Pro forma net presentation, asset 94.6 75.9
Counterparties without Offsetting Position [Member]    
Derivative Asset [Abstract]    
Gross asset 49.1 40.5
Pro forma net presentation, asset, total 49.1 40.5
Current Assets from Risk Management Activities [Member]    
Derivative Asset [Abstract]    
Gross asset 140.1 115.3
Pro forma net presentation, asset, current 98.7 85.3
Current Assets from Risk Management Activities [Member] | Counterparties with Offsetting Positions or Collateral [Member]    
Derivative Asset [Abstract]    
Gross asset 103.9 100.0
Pro forma net presentation, asset 62.5 70.0
Current Assets from Risk Management Activities [Member] | Counterparties without Offsetting Position [Member]    
Derivative Asset [Abstract]    
Gross asset 36.2 15.3
Pro forma net presentation, asset, current 36.2 15.3
Long-Term Assets from Risk Management Activities [Member]    
Derivative Asset [Abstract]    
Gross asset 60.0 34.1
Pro forma net presentation, asset, noncurrent 45.0 31.1
Long-Term Assets from Risk Management Activities [Member] | Counterparties with Offsetting Positions or Collateral [Member]    
Derivative Asset [Abstract]    
Gross asset 47.1 8.9
Pro forma net presentation, asset 32.1 5.9
Long-Term Assets from Risk Management Activities [Member] | Counterparties without Offsetting Position [Member]    
Derivative Asset [Abstract]    
Gross asset 12.9 25.2
Pro forma net presentation, asset, noncurrent $ 12.9 $ 25.2