Income Tax Expense (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Income Tax Expense [Table Text Block]

Income Tax Expense
Year Ended December 31	2020	2019	2018
Millions
Current Income Tax Expense (a)
Federal	—	—	—
State	—	$0.1	$0.3
Total Current Income Tax Expense	—	$0.1	$0.3
Deferred Income Tax Expense (Benefit)
Federal (b)	$(48.8)	$(27.8)	$(26.2)
State	9.8	21.7	11.0
Investment Tax Credit Amortization	(0.5)	(0.6)	(0.6)
Total Deferred Income Tax Expense (Benefit)	$(39.5)	$(6.7)	$(15.8)
Total Income Tax Expense (Benefit)	$(39.5)	$(6.6)	$(15.5)

(a)For the years ended December 31, 2020, 2019 and 2018, the federal and state current tax expense was minimal due to NOLs which resulted from the bonus depreciation provisions of the Protecting Americans from Tax Hikes Act of 2015, the Tax Increase Prevention Act of 2014 and the American Taxpayer Relief Act of 2012. Federal and state NOLs are being carried forward to offset current and future taxable income.

(b)For the years ended December 31, 2020, 2019 and 2018, the federal tax benefit is primarily due to production tax credits.

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	2020		2019		2018
Millions
Income Before Non-Controlling Interest and Income Taxes	$122.1		$178.9		$158.6
Statutory Federal Income Tax Rate	21	%	21	%	21	%
Income Taxes Computed at Statutory Federal Rate	$25.6		$37.6		$33.3
Increase (Decrease) in Tax Due to:
State Income Taxes – Net of Federal Income Tax Benefit	7.7		17.2		8.9
Production Tax Credits	(62.7)		(50.7)		(45.0)
Regulatory Differences – Excess Deferred Tax Benefit (a)	(9.9)		(8.8)		(8.2)
U.S. Water Services Sale of Stock Basis Difference	—		1.7		—
Change in Fair Value of Contingent Consideration	—		—		(0.4)
Non-Controlling Interest	2.7		—		—
Other	(2.9)		(3.6)		(4.1)
Total Income Tax Expense (Benefit)	$(39.5)		$(6.6)		$(15.5)

(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	2020	2019
Millions
Deferred Income Tax Assets
Employee Benefits and Compensation	$67.6	$49.9
Property-Related	61.4	76.9
NOL Carryforwards	60.7	63.2
Tax Credit Carryforwards	455.7	395.5
Power Sales Agreements	20.1	23.7
Regulatory Liabilities	107.7	116.9
Other	22.4	23.4
Gross Deferred Income Tax Assets	795.6	749.5
Deferred Income Tax Asset Valuation Allowance	(69.9)	(70.0)
Total Deferred Income Tax Assets	$725.7	$679.5
Deferred Income Tax Liabilities
Property-Related	$691.5	$713.4
Regulatory Asset for Benefit Obligations	71.5	54.5
Unamortized Investment Tax Credits	31.1	31.6
Partnership Basis Differences	86.7	49.4
Regulatory Assets	32.6	35.4
Other	8.0	8.0
Total Deferred Income Tax Liabilities	$921.4	$892.3
Net Deferred Income Taxes (a)	$195.7	$212.8

(a)Recorded as a net long-term 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	2020	2019
Millions
Federal NOL Carryforwards (a)	$197.5	$211.3
Federal Tax Credit Carryforwards	$362.9	$302.5
State NOL Carryforwards (a)	$270.1	$274.8
State Tax Credit Carryforwards (b)	$23.4	$23.4

(a)Pre-tax amounts.

(b)Net of a $69.4 million valuation allowance as of December 31, 2020 ($69.6 million as of December 31, 2019).

Gross Unrecognized Income Tax Benefits [Table Text Block]

Gross Unrecognized Income Tax Benefits	2020	2019	2018
Millions
Balance at January 1	$1.4	$1.6	$1.7
Additions for Tax Positions Related to the Current Year	0.1	0.1	0.1
Additions for Tax Positions Related to Prior Years	—	0.1	0.1
Reductions for Tax Positions Related to Prior Years	(0.1)	(0.4)	(0.2)
Lapse of Statute	—	—	(0.1)
Balance as of December 31	$1.4	$1.4	$1.6