Derivative Instruments (Tables)

12 Months Ended

Dec. 31, 2019

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of derivative assets and liabilities

The following table shows our derivative assets and derivative liabilities, along with their classification on our balance sheets. None of our derivatives are designated as hedging instruments.

	December 31, 2019				December 31, 2018
(in millions)	Derivative Assets		Derivative Liabilities		Derivative Assets		Derivative Liabilities
Other current
Natural gas contracts	$	0.4	$	5.1	$	0.7	$	1.2
FTRs	1.5		—		4.4		—
Coal contracts	—		0.2		—		0.1
Total other current	1.9		5.3		5.1		1.3
Other long-term
Natural gas contracts	—		0.1		—		—
Coal contracts	0.1		—		—		—
Total other long-term	0.1		0.1		—		—
Total	$	2.0	$	5.4	$	5.1	$	1.3

Schedule of estimated notional sales volumes and realized gains (losses)

Our estimated notional sales volumes and realized gains (losses) were as follows for the years ended:

	December 31, 2019				December 31, 2018			December 31, 2017
(in millions)	Volume	Gains (Losses)			Volume	Gains		Volume	Gains (Losses)
Natural gas contracts	61.6 Dth	$	(11.3	)	53.4 Dth	$	9.7	26.9 Dth	$	(1.0	)
Petroleum products contracts	— gallons	—			4.2 gallons	1.2		16.7 gallons	(1.4		)
FTRs	21.7 MWh	8.7			21.2 MWh	3.4		27.1 MWh	7.6
Total		$	(2.6	)		$	14.3		$	5.2

Schedule of net derivative instruments

The following table shows derivative assets and derivative liabilities if derivative instruments by counterparty were presented net on our balance sheets:

	December 31, 2019							December 31, 2018
(in millions)	Derivative Assets			Derivative Liabilities				Derivative Assets			Derivative Liabilities
Gross amount recognized on the balance sheet	$	2.0		$	5.4			$	5.1		$	1.3
Gross amount not offset on the balance sheet	(0.4		)	(5.2		)	(1)	(0.6		)	(1.3		)	(2)
Net amount	$	1.6		$	0.2			$	4.5		$	—

⁽¹⁾   Includes cash collateral posted of $4.8 million.

⁽²⁾  

Includes cash collateral posted of $0.7 million.