Regulatory Assets and Liabilities (Tables)

12 Months Ended

Dec. 31, 2023

Regulatory Assets and Liabilities Disclosure [Abstract]

The following table summarizes the individual components of unamortized regulatory assets and liabilities as of December 31:


	Estimated Recovery or Refund Period	*	2023		2022
			(In thousands)
Regulatory assets:
Current:
Natural gas costs recoverable through rate adjustments	Up to 1 year		$	98,844	$	141,306
Electric fuel and purchased power deferral	Up to 1 year		33,918		2,656
Conservation programs	Up to 1 year		14,425		8,544
Cost recovery mechanisms	Up to 1 year		9,153		4,019
Environmental compliance programs	Up to 1 year		5,525		—
Other	Up to 1 year		10,627		8,567
			172,492		165,092
Noncurrent:
Pension and postretirement benefits	**		142,511		143,349
Cost recovery mechanisms	Up to 25 years		85,944		67,171
Environmental compliance programs	-		66,806		—
Natural gas costs recoverable through rate adjustments	Up to 2 years		55,493		—
Plant costs/asset retirement obligations	Over plant lives		46,009		44,462
Manufactured gas plant site remediation	-		26,127		26,624
Taxes recoverable from customers	Over plant lives		12,249		12,330
Long-term debt refinancing costs	Up to 37 years		2,600		3,188
Plant to be retired	-		772		21,525
Other	Up to 15 years		8,588		11,010
			447,099		329,659
Total regulatory assets			$	619,591	$	494,751
Regulatory liabilities:
Current:
Natural gas costs refundable through rate adjustments	Up to 1 year		$	43,161	$	955
Provision for rate refund	Up to 1 year		6,866		1,147
Cost recovery mechanisms	Up to 1 year		6,284		1,977
Margin sharing	Up to 1 year		5,243		—
Taxes refundable to customers	Up to 1 year		2,149		3,937
Conservation programs	Up to 1 year		2,130		4,126
Refundable fuel & electric costs	Up to 1 year		263		3,253
Electric fuel and purchased power deferral	Up to 1 year		—		4,929
Other	Up to 1 year		4,665		6,116
			70,761		26,440
Noncurrent:
Plant removal and decommissioning costs	Over plant lives		220,147		208,650
Taxes refundable to customers	Over plant lives		193,578		203,222
Environmental compliance programs	-		61,941		—
Cost recovery mechanisms	Up to 18 years		21,791		14,025
Accumulated deferred investment tax credit	Over plant lives		15,740		13,594
Pension and postretirement benefits	**		6,044		7,376
Other	Up to 14 years		1,809		1,587
			521,050		448,454
Total regulatory liabilities			$	591,811	$	474,894
Net regulatory position			$	27,780	$	19,857

*Estimated recovery or refund period for amounts currently being recovered or refunded in rates to customers.

** Recovered as expense is incurred or cash contributions are made.

Schedule of Regulatory Liabilities

The following table summarizes the individual components of unamortized regulatory assets and liabilities as of December 31:


	Estimated Recovery or Refund Period	*	2023		2022
			(In thousands)
Regulatory assets:
Current:
Natural gas costs recoverable through rate adjustments	Up to 1 year		$	98,844	$	141,306
Electric fuel and purchased power deferral	Up to 1 year		33,918		2,656
Conservation programs	Up to 1 year		14,425		8,544
Cost recovery mechanisms	Up to 1 year		9,153		4,019
Environmental compliance programs	Up to 1 year		5,525		—
Other	Up to 1 year		10,627		8,567
			172,492		165,092
Noncurrent:
Pension and postretirement benefits	**		142,511		143,349
Cost recovery mechanisms	Up to 25 years		85,944		67,171
Environmental compliance programs	-		66,806		—
Natural gas costs recoverable through rate adjustments	Up to 2 years		55,493		—
Plant costs/asset retirement obligations	Over plant lives		46,009		44,462
Manufactured gas plant site remediation	-		26,127		26,624
Taxes recoverable from customers	Over plant lives		12,249		12,330
Long-term debt refinancing costs	Up to 37 years		2,600		3,188
Plant to be retired	-		772		21,525
Other	Up to 15 years		8,588		11,010
			447,099		329,659
Total regulatory assets			$	619,591	$	494,751
Regulatory liabilities:
Current:
Natural gas costs refundable through rate adjustments	Up to 1 year		$	43,161	$	955
Provision for rate refund	Up to 1 year		6,866		1,147
Cost recovery mechanisms	Up to 1 year		6,284		1,977
Margin sharing	Up to 1 year		5,243		—
Taxes refundable to customers	Up to 1 year		2,149		3,937
Conservation programs	Up to 1 year		2,130		4,126
Refundable fuel & electric costs	Up to 1 year		263		3,253
Electric fuel and purchased power deferral	Up to 1 year		—		4,929
Other	Up to 1 year		4,665		6,116
			70,761		26,440
Noncurrent:
Plant removal and decommissioning costs	Over plant lives		220,147		208,650
Taxes refundable to customers	Over plant lives		193,578		203,222
Environmental compliance programs	-		61,941		—
Cost recovery mechanisms	Up to 18 years		21,791		14,025
Accumulated deferred investment tax credit	Over plant lives		15,740		13,594
Pension and postretirement benefits	**		6,044		7,376
Other	Up to 14 years		1,809		1,587
			521,050		448,454
Total regulatory liabilities			$	591,811	$	474,894
Net regulatory position			$	27,780	$	19,857

*Estimated recovery or refund period for amounts currently being recovered or refunded in rates to customers.

** Recovered as expense is incurred or cash contributions are made.