FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 30, 2023

Fair Value Disclosures [Abstract]

Schedule of fair value of assets and liabilities measured on a recurring basis categorized by level within the fair value hierarchy

The following tables summarize our financial assets and liabilities that were accounted for at fair value on a recurring basis, categorized by level within the fair value hierarchy:

	June 30, 2023
(in millions)	Level 1		Level 2		Level 3		Total
Derivative assets
Natural gas contracts	$	2.8	$	7.7	$	—	$	10.5
FTRs and TCRs	—		—		16.8		16.8
Coal contracts	—		1.2		—		1.2
Total derivative assets	$	2.8	$	8.9	$	16.8	$	28.5
Investments held in rabbi trust	$	47.8	$	—	$	—	$	47.8
Derivative liabilities
Natural gas contracts	$	100.3	$	12.0	$	—	$	112.3
Coal contracts	—		28.1		—		28.1
Total derivative liabilities	$	100.3	$	40.1	$	—	$	140.4

	December 31, 2022
(in millions)	Level 1		Level 2		Level 3		Total
Derivative assets
Natural gas contracts	$	16.3	$	16.2	$	—	$	32.5
FTRs	—		—		7.8		7.8
Coal contracts	—		34.5		—		34.5
Total derivative assets	$	16.3	$	50.7	$	7.8	$	74.8
Investments held in rabbi trust	$	50.9	$	—	$	—	$	50.9
Derivative liabilities
Natural gas contracts	$	81.4	$	15.2	$	—	$	96.6

Reconciliation of changes in fair value of items categorized as level 3 measurements

The following table summarizes the changes to derivatives classified as Level 3 in the fair value hierarchy:

	Three Months Ended June 30				Six Months Ended June 30
(in millions)	2023		2022		2023		2022
Balance at the beginning of the period	$	3.0	$	1.0	$	7.8	$	2.4
Purchases	19.2		21.9		19.5		21.9
Realized and unrealized net gains (losses) included in earnings (1)	(0.2)		1.8		(0.5)		1.8
Settlements	(5.2)		(4.8)		(10.0)		(6.2)
Balance at the end of the period	$	16.8	$	19.9	$	16.8	$	19.9
Unrealized net gains (losses) included in earnings attributable to Level 3 derivatives held at the end of the reporting period (1)	$	(0.1)	$	0.9	$	(0.1)	$	0.9

(1)Amounts relate to FTRs and TCRs included in our non-utility energy infrastructure segment. These realized and unrealized net gains and losses are recorded in operating revenues on our income statements.

Schedule of carrying value and fair value of financial instruments not recorded at fair value

The following table shows the financial instruments included on our balance sheets that were not recorded at fair value:

	June 30, 2023				December 31, 2022
(in millions)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Preferred stock of subsidiary	$	30.4	$	22.8	$	30.4	$	22.7
Long-term debt, including current portion (1)	16,835.4		15,366.6		15,464.2		13,921.3

(1)The carrying amount of long-term debt excludes finance lease obligations of $150.4 million and $183.2 million at June 30, 2023 and December 31, 2022, respectively.