REGULATORY ASSETS AND LIABILITIES (Tables)

9 Months Ended

Sep. 30, 2021

Regulatory Assets and Liabilities Disclosure [Abstract]

Schedule of regulatory assets

(in millions)	September 30, 2021		December 31, 2020
Regulatory assets
Pension and OPEB costs	$	145.9	$	161.4
Environmental remediation costs	113.0		116.1
Income tax related items	53.7		46.7
Plant retirements	52.4		58.5
ReACT™	16.2		18.2
AROs	14.0		13.1
Uncollectible expense	4.7		12.5
Forward Wind Energy Center	4.7		10.3
Other, net	10.2		12.6
Total regulatory assets	$	414.8	$	449.4

Schedule of regulatory liabilities

(in millions)	September 30, 2021		December 31, 2020
Regulatory liabilities
Income tax related items	$	363.4	$	397.0
Removal costs	192.4		193.7
Pension and OPEB benefits	115.4		115.9
Derivatives (1)	59.2		3.1
Earnings sharing mechanism	25.1		36.8
Electric transmission costs	19.5		16.8
Energy costs refundable through rate adjustments	1.0		9.7
Other, net	2.1		3.2
Total regulatory liabilities	$	778.1	$	776.2
Balance sheet presentation
Other current liabilities	$	1.0	$	3.6
Regulatory liabilities	777.1		772.6
Total regulatory liabilities	$	778.1	$	776.2

(1)    For most energy-related physical and financial contracts that qualify as derivatives, the PSCW allows the effects of fair value accounting to be offset to regulatory assets and liabilities. See Note 12, Derivative Instruments, for more information.