Regulatory Matters (Tables)

6 Months Ended

Jun. 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 June 30, 2023 and December 31, 2022 and the period we expect to recover or refund such amounts:


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

Regulatory Assets
Pension and Other Postretirement Benefit Plans1	Various	$	—	$	90,602	$	—	$	88,354
Alternative Revenue Program Riders2	Up to 2 years	6,563		79		5,679		2,508
Asset Retirement Obligations1	Asset lives	—		2,327		—		1,467
Deferred Income Taxes	Asset lives	—		847		—		—
ISO Cost Recovery Trackers1	Up to 2 years	288		207		575		314
Unrecovered Project Costs1	Up to 4 years	349		1,048		320		990
Deferred Rate Case Expenses1	Up to 3 years	377		566		377		754
Fuel Clause Adjustments1	Up to 1 year	9,935		—		10,893		—
Derivative Instruments1	Up to 2 years	1,521		207		7,130		—
Other1	Various	25		245		25		268
Total Regulatory Assets		$	19,058	$	96,128	$	24,999	$	94,655
Regulatory Liabilities
Deferred Income Taxes	Asset lives	$	—	$	129,567	$	—	$	131,480
Plant Removal Obligations	Asset lives	8,474		106,393		8,509		105,733
Fuel Clause Adjustments	Up to 1 year	22,358		—		365		—
Alternative Revenue Program Riders	Up to 1 year	4,560		—		2,504		—
North Dakota PTC Refunds	Asset lives	—		9,512		—		7,136
Pension and Other Postretirement Benefit Plans	Up to 1 year	5,589		—		5,589		—



Other	Various	762		463		333		148
Total Regulatory Liabilities		$	41,743	$	245,935	$	17,300	$	244,497

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