Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2020

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, 2020 and 2019 and the period we expect to recover or refund such amounts:


	Period of	2020				2019
(in thousands)	Recovery/Refund	Current		Long-Term		Current		Long Term

Regulatory Assets
Pension and Other Postretirement Benefit Plans1	See below	$	11,037	$	146,071	$	9,090	$	130,783
Alternative Revenue Program Riders2	Up to 3 years	8,871		9,373		8,464		2,844
Asset Retirement Obligations1	Asset lives	—		8,462		—		7,772

ISO Cost Recovery Trackers1	Up to 2 years	1,079		867		2,033		1,170
Unrecovered Project Costs1	Up to 3 years	361		2,989		859		478
Deferred Rate Case Expenses1	Various	360		230		260		489
Debt Reacquisition Premiums1	Up to 30 years	192		341		201		548
Other1	Various	—		62		743		54
Total Regulatory Assets		$	21,900	$	168,395	$	21,650	$	144,138
Regulatory Liabilities
Deferred Income Taxes	Asset lives	$	—	$	134,719	$	—	$	141,707
Plant Removal Obligations	Asset lives	—		98,707		—		97,726
Fuel Clause Adjustment	Up to 1 year	10,947		—		3,982		—
Alternative Revenue Program Riders	Up to 1 year	3,581		470		2,857		—
Pension and Other Postretirement Benefit Plans	Up to 1 year	1,959		—		471		—
Deferred Rate Case Expenses	Various	—		—		—		401
ISO Cost Recovery Trackers	Up to 2 years	—		10		—		—
Other	Various	176		67		170		72
Total Regulatory Liabilities		$	16,663	$	233,973	$	7,480	$	239,906

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