Regulatory assets and liabilities

9 Months Ended

Sep. 30, 2024

Regulatory Assets and Liabilities Disclosure [Abstract]

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


	Estimated Recovery or Refund Period as of September 30, 2024	*	September 30, 2024		September 30, 2023		December 31, 2023
			(In thousands)
Regulatory assets:
Current:
Natural gas costs recoverable through rate adjustments	Up to 1 year		$	111,946	$	107,101	$	98,844
Environmental compliance programs	Up to 1 year		80,198		3,972		5,525
Conservation programs	Up to 1 year		19,059		14,411		14,425
Demand cost deferral	Up to 1 year		13,898		13,254		5,207
Electric fuel and purchased power deferral	Up to 1 year		4,497		17,775		33,918
Cost recovery mechanisms	Up to 1 year		4,332		9,461		9,153
Other	Up to 1 year		7,078		3,274		5,420
			241,008		169,248		172,492
Noncurrent:
Pension and postretirement benefits	**		142,511		144,448		142,511
Cost recovery mechanisms	Up to 25 years		82,907		68,539		85,944
Plant costs/asset retirement obligations	Over plant lives		45,249		43,520		46,009
Manufactured gas plant site remediation	-		25,789		24,577		26,127
Taxes recoverable from customers	Over plant lives		12,316		12,266		12,249
Natural gas costs recoverable through rate adjustments	Up to 2 years		11,707		64,914		55,493
Electric fuel and purchased power deferral	Up to 2 years		8,335		—		—
Environmental compliance programs	-		2,858		36,605		66,806
Long-term debt refinancing costs	Up to 36 years		2,159		2,747		2,600
Plant to be retired	-		22		19,947		772
Other	Up to 15 years		9,725		11,406		8,588
			343,578		428,969		447,099
Total regulatory assets			$	584,586	$	598,217	$	619,591
Regulatory liabilities:
Current:
Environmental compliance programs	Up to 1 year		$	77,392	$	—	$	—
Natural gas costs refundable through rate adjustments	Up to 1 year		54,197		20,445		43,161
Provision for rate refund	Up to 1 year		8,868		2,717		6,866
Margin sharing	Up to 1 year		3,945		2,697		5,243
Conservation programs	Up to 1 year		2,662		1,976		2,130
Cost recovery mechanisms	Up to 1 year		2,634		5,754		6,284
Taxes refundable to customers	Up to 1 year		2,195		1,513		2,149
Other	Up to 1 year		5,175		9,911		4,928
			157,068		45,013		70,761
Noncurrent:
Plant removal and decommissioning costs	Over plant lives		224,839		220,499		220,147
Taxes refundable to customers	Over plant lives		184,715		194,804		193,578
Cost recovery mechanisms	Up to 18 years		28,397		20,012		21,791
Accumulated deferred investment tax credit	Over plant lives		17,679		14,800		15,740
Pension and postretirement benefits	**		6,043		7,120		6,044
Environmental compliance programs	-		—		36,126		61,941
Other	Up to 14 years		2,117		1,751		1,809
			463,790		495,112		521,050
Total regulatory liabilities			$	620,858	$	540,125	$	591,811
Net regulatory position			$	(36,272)	$	58,092	$	27,780

*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.

At September 30, 2024 and 2023, and December 31, 2023, approximately $178.8 million, $211.8 million and $194.3 million, respectively, of regulatory assets were not earning a rate of return; however, these regulatory assets are expected to be recovered from customers in future rates. These assets are largely comprised of the unfunded portion of pension and postretirement benefits, asset retirement obligations, certain pipeline integrity costs and the estimated future cost of manufactured gas plant site remediation.

If, for any reason, the Company's regulated businesses cease to meet the criteria for application of regulatory accounting for all or part of their operations, the regulatory assets and liabilities relating to those portions ceasing to meet such criteria would be written off and included in the statement of income or accumulated other comprehensive loss in the period in which the discontinuance of regulatory accounting occurs.