Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2021

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 December 31, 2021 and 2020 and the period we expect to recover or refund such amounts:


	Period of	2021				2020
(in thousands)	Recovery/Refund	Current		Long-Term		Current		Long-Term

Regulatory Assets
Pension and Other Postretirement Benefit Plans1	See below	$	7,791	$	114,961	$	11,037	$	146,071
Alternative Revenue Program Riders2	Up to 2 years	11,889		5,564		8,871		9,373
Asset Retirement Obligations1	Asset lives	—		742		—		8,462

ISO Cost Recovery Trackers1	Up to 2 years	—		1,342		1,079		867
Unrecovered Project Costs1	Up to 5 years	2,136		1,455		361		2,989
Deferred Rate Case Expenses1	Various	607		1,131		360		230
Debt Reacquisition Premiums1	Up to 30 years	100		240		192		341
Fuel Clause Adjustments1	Up to 1 year	4,819		—		—		—
Other1	Various	—		73		—		62
Total Regulatory Assets		$	27,342	$	125,508	$	21,900	$	168,395
Regulatory Liabilities
Deferred Income Taxes	Asset lives	$	—	$	129,437	$	—	$	134,719
Plant Removal Obligations	Asset lives	8,306		101,595		—		98,707
Fuel Clause Adjustments	Up to 1 year	1,554		—		10,947		—
Alternative Revenue Program Riders	Various	5,772		3,336		3,581		470
Pension and Other Postretirement Benefit Plans	Up to 1 year	2,603		—		1,959		—

Derivative Instruments	Up to 1 year	6,214		—		—		—

Other	Various	395		62		176		77
Total Regulatory Liabilities		$	24,844	$	234,430	$	16,663	$	233,973

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