Risk Management Activities (Tables)

6 Months Ended

Jun. 30, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]

Risk management assets and liabilities on our derivatives are presented on the Condensed Consolidated Balance Sheets (unaudited) as shown below:

(in millions)	June 30, 2018		December 31, 2017
Risk Management Assets - Current(1)
Interest rate risk programs	$	1.7	$	14.0
Commodity price risk programs	0.5		0.5
Total	$	2.2	$	14.5
Risk Management Assets - Noncurrent(2)
Interest rate risk programs	$	23.5	$	5.6
Commodity price risk programs	1.8		1.0
Total	$	25.3	$	6.6
Risk Management Liabilities - Current
Interest rate risk programs	$	—	$	38.6
Commodity price risk programs	4.0		4.6
Total	$	4.0	$	43.2
Risk Management Liabilities - Noncurrent
Interest rate risk programs	$	—	$	—
Commodity price risk programs	44.9		28.5
Total	$	44.9	$	28.5

⁽¹⁾Presented in "Prepayments and other" on the Condensed Consolidated Balance Sheets (unaudited).

⁽²⁾Presented in "Deferred charges and other" on the Condensed Consolidated Balance Sheets (unaudited).