Regulatory assets and liabilities

3 Months Ended

Mar. 31, 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 March 31, 2024	*	March 31, 2024		March 31, 2023		December 31, 2023
			(In thousands)
Regulatory assets:
Current:
Natural gas costs recoverable through rate adjustments	Up to 1 year		$	110,481	$	198,166	$	98,844
Electric fuel and purchased power deferral	Up to 1 year		17,061		3,279		33,918
Conservation programs	Up to 1 year		13,735		8,599		14,425
Environmental compliance programs	Up to 1 year		7,443		1,191		5,525
Cost recovery mechanisms	Up to 1 year		6,454		3,954		9,153
Other	Up to 1 year		3,440		1,129		10,627
			158,614		216,318		172,492
Noncurrent:
Pension and postretirement benefits	**		142,511		143,349		142,511
Cost recovery mechanisms	Up to 25 years		84,546		65,732		85,944
Environmental compliance programs	-		50,372		21,942		66,806
Plant costs/asset retirement obligations	Over plant lives		45,702		44,131		46,009
Natural gas costs recoverable through rate adjustments	Up to 2 years		25,915		—		55,493
Manufactured gas plant site remediation	-		25,851		26,605		26,127
Taxes recoverable from customers	Over plant lives		12,331		12,198		12,249
Electric fuel and purchased power deferral	Up to 2 years		15,612		—		—
Long-term debt refinancing costs	Up to 36 years		2,453		3,041		2,600
Plant to be retired	-		294		21,072		772
Other	Up to 15 years		8,846		11,430		8,588
			414,433		349,500		447,099
Total regulatory assets			$	573,047	$	565,818	$	619,591
Regulatory liabilities:
Current:
Natural gas costs refundable through rate adjustments	Up to 1 year		$	54,282	$	6,331	$	43,161
Provision for rate refund	Up to 1 year		6,517		1,115		6,866
Cost recovery mechanisms	Up to 1 year		5,642		2,926		6,284
Conservation programs	Up to 1 year		3,576		3,834		2,130
Margin sharing	Up to 1 year		2,869		—		5,243
Taxes refundable to customers	Up to 1 year		1,991		1,513		2,149
Refundable fuel and electric costs	Up to 1 year		1,122		1,179		263
Electric fuel and purchased power deferral	Up to 1 year		746		9,630		—
Other	Up to 1 year		13,370		17,867		4,665
			90,115		44,395		70,761
Noncurrent:
Plant removal and decommissioning costs	Over plant lives		220,519		214,467		220,147
Taxes refundable to customers	Over plant lives		190,850		200,879		193,578
Environmental compliance programs	-		63,746		—		61,941
Cost recovery mechanisms	Up to 18 years		24,269		16,313		21,791
Accumulated deferred investment tax credit	Over plant lives		16,129		13,996		15,740
Pension and postretirement benefits	**		6,044		7,376		6,044
Other	Up to 14 years		1,927		1,638		1,809
			523,484		454,669		521,050
Total regulatory liabilities			$	613,599	$	499,064	$	591,811
Net regulatory position			$	(40,552)	$	66,754	$	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 March 31, 2024 and 2023, and December 31, 2023, approximately $191.7 million, $255.6 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.