Regulatory Matters (Tables)

9 Months Ended

Sep. 30, 2023

Regulatory Assets and Liabilities Disclosure [Abstract]

Schedule of Regulatory Assets and Liabilities

The following presents our current and long-term regulatory assets and liabilities as of September 30, 2023 and December 31, 2022 and the period we expect to recover or refund such amounts:


	Period of	September 30, 2023				December 31, 2022
(in thousands)	Recovery/Refund	Current		Long-Term		Current		Long-Term

Regulatory Assets
Pension and Other Postretirement Benefit Plans1	Various	$	—	$	86,286	$	—	$	88,354
Alternative Revenue Program Riders2	Up to 2 years	5,780		118		5,679		2,508
Asset Retirement Obligations1	Asset lives	—		—		—		1,467
Deferred Income Taxes	Asset lives	—		931		—		—
ISO Cost Recovery Trackers1	Up to 2 years	144		260		575		314
Unrecovered Project Costs1	Up to 4 years	349		962		320		990
Deferred Rate Case Expenses1	Up to 3 years	377		471		377		754
Fuel Clause Adjustments1	Up to 1 year	9,141		—		10,893		—
Derivative Instruments1	Up to 2 years	1,225		228		7,130		—
Other1	Various	25		235		25		268
Total Regulatory Assets		$	17,041	$	89,491	$	24,999	$	94,655
Regulatory Liabilities
Deferred Income Taxes	Asset lives	$	—	$	128,886	$	—	$	131,480
Plant Removal Obligations	Asset lives	8,456		117,359		8,509		105,733
Fuel Clause Adjustments	Up to 1 year	12,217		—		365		—
Alternative Revenue Program Riders	Up to 1 year	8,426		—		2,504		—
North Dakota PTC Refunds	Asset lives	—		10,281		—		7,136
Pension and Other Postretirement Benefit Plans	Various	2,279		19,026		5,589		—



Other	Various	907		257		333		148
Total Regulatory Liabilities		$	32,285	$	275,809	$	17,300	$	244,497

1Costs subject to recovery without a rate of return.
2Amount eligible for recovery includes an incentive or rate of return.