Income Tax Expense (Tables)

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Income Tax Expense [Table Text Block]

Income Tax Expense
Year Ended December 31	2022	2021	2020
Millions
Current Income Tax Expense (a)
Federal	$1.2	—	—
State	6.1	—	—
Total Current Income Tax Expense	$7.3	—	—
Deferred Income Tax Expense (Benefit)
Federal (b)	$(32.8)	$(37.2)	$(51.5)
State (c)	(5.2)	10.8	8.6
Investment Tax Credit Amortization	(0.5)	(0.5)	(0.5)
Total Deferred Income Tax Expense (Benefit)	$(38.5)	$(26.9)	$(43.4)
Total Income Tax Expense (Benefit)	$(31.2)	$(26.9)	$(43.4)

(a)For the years ended December 31, 2021 and 2020, the federal and state current tax expense was minimal due to NOLs which resulted from the bonus depreciation provisions of certain tax legislation. Federal and state NOLs are being carried forward to offset current and future taxable income. For the year ended December 31, 2022, federal NOLs were fully utilized and production tax credits were used to partially offset federal taxable income.

(b)For the years ended December 31, 2022, 2021 and 2020, the federal tax benefit is primarily due to production tax credits.

(c)For the year ended December 31, 2022, the state impact includes the benefit of deferred repricing as a result of the New Energy acquisition.

Reconciliation of Taxes from Federal Statutory Rate to Total Income Tax Expense [Table Text Block]

Reconciliation of Taxes from Federal Statutory
Rate to Total Income Tax Expense
Year Ended December 31	2022		2021		2020
Millions
Income Before Non-Controlling Interest and Income Taxes	$100.1		$110.9		$109.4
Statutory Federal Income Tax Rate	21	%	21	%	21	%
Income Taxes Computed at Statutory Federal Rate	$21.0		$23.3		$23.0
Increase (Decrease) in Tax Due to:
State Income Taxes	8.6		8.6		6.5
Deferred Income Tax Revaluation	(7.9)		—		—
Production Tax Credits	(50.7)		(53.5)		(62.7)
Investment Tax Credits	(4.1)		—		—
Regulatory Differences – Excess Deferred Tax Benefit (a)	(9.1)		(9.5)		(9.9)
Non-Controlling Interest	11.2		6.3		2.7
AFUDC - Equity	(1.1)		(1.0)		(0.8)
Other	0.9		(1.1)		(2.2)
Total Income Tax Benefit	$(31.2)		$(26.9)		$(43.4)

(a)Excess deferred income taxes are being returned to customers under both the Average Rate Assumption Method and amortization periods as approved by regulators. (See Note 4. Regulatory Matters.)

Deferred Tax Assets and Liabilities [Table Text Block]

Deferred Income Tax Assets and Liabilities
As of December 31	2022	2021
Millions
Deferred Income Tax Assets
Employee Benefits and Compensation	$46.4	$44.5
Property-Related	61.9	54.8
NOL Carryforwards	16.7	67.5
Capital Loss Carryforwards	13.1	—
Tax Credit Carryforwards	548.7	509.1
Power Sales Agreements	13.7	16.5
Regulatory Liabilities	95.5	101.5
Other	28.1	18.0
Gross Deferred Income Tax Assets	824.1	811.9
Deferred Income Tax Asset Valuation Allowance	(60.2)	(69.0)
Total Deferred Income Tax Assets	$763.9	$742.9
Deferred Income Tax Liabilities
Deferred Gain	$7.9	$7.9
Property-Related	661.7	680.8
Regulatory Asset for Benefit Obligations	57.7	54.9
Unamortized Investment Tax Credits	30.0	30.5
Partnership Basis Differences	126.0	106.3
Fuel Adjustment Clause	10.7	14.3
Regulatory Assets	28.0	30.0
Total Deferred Income Tax Liabilities	$922.0	$924.7
Net Deferred Income Taxes (a)	$158.1	$181.8

(a)Recorded as a net Deferred Income Tax liability on the Consolidated Balance Sheet.

NOL and Tax Credit Carryforwards [Table Text Block]

NOL and Tax Credit Carryforwards
As of December 31	2022	2021
Millions
Federal NOL Carryforwards (a)	—	$177.3
Federal Tax Credit Carryforwards	$464.5	$416.4
Federal Capital Loss (a)	$35.1	—
State NOL Carryforwards (a)	$323.0	$506.9
State Tax Credit Carryforwards (b)	$24.5	$24.2
State Capital Loss (a)	$83.2	—

(a)Pre-tax amounts.

(b)Net of a $59.6 million valuation allowance as of December 31, 2022 ($68.6 million as of December 31, 2021).

Gross Unrecognized Income Tax Benefits [Table Text Block]

Gross Unrecognized Income Tax Benefits	2022	2021	2020
Millions
Balance at January 1	$1.3	$1.4	$1.4
Additions for Tax Positions Related to the Current Year	—	—	0.1
Reductions for Tax Positions Related to Prior Years	—	(0.1)	(0.1)
Balance as of December 31	$1.3	$1.3	$1.4