Regulatory assets and liabilities (Tables)

3 Months Ended

Mar. 31, 2020

Regulatory Assets and Liabilities Disclosure [Abstract]

Regulatory Assets

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

	Estimated Recovery Period as of March 31, 2020	*	March 31, 2020			March 31, 2019			December 31, 2019
			(In thousands)
Regulatory assets:
Current:
Natural gas costs recoverable through rate adjustments	Up to 1 year		$	39,805		$	61,236		$	42,823
Cost recovery mechanisms	Up to 1 year		6,686			6,661			6,288
Conservation programs	Up to 1 year		6,303			5,613			6,963
Other	Up to 1 year		2,412			984			7,539
			55,206			74,494			63,613
Noncurrent:
Pension and postretirement benefits	**		157,051			165,879			157,069
Asset retirement obligations	Over plant lives		67,475			63,633			66,000
Plant to be retired	-		41,080			6,691			32,931
Natural gas costs recoverable through rate adjustments	Up to 3 years		33,027			30,229			46,381
Manufactured gas plant site remediation	-		15,699			17,064			15,126
Cost recovery mechanisms	Up to 10 years		11,891			11,174			13,108
Taxes recoverable from customers	Over plant lives		11,082			11,858			11,486
Long-term debt refinancing costs	Up to 17 years		4,133			4,746			4,286
Costs related to identifying generation development	Up to 7 years		1,937			2,394			2,052
Other	Up to 19 years		4,814			5,451			5,345
			348,189			319,119			353,784
Total regulatory assets			$	403,395		$	393,613		$	417,397
Regulatory liabilities:
Current:
Natural gas costs refundable through rate adjustments			$	32,181		$	29,739		$	23,825
Taxes refundable to customers			4,002			8,139			3,472
Other			23,889			23,512			15,638
			60,072			61,390			42,935
Noncurrent:
Taxes refundable to customers			240,148			259,638			246,034
Plant removal and decommissioning costs			174,120			172,569			173,722
Pension and postretirement benefits			18,040			15,239			18,065
Other			10,897			9,638			9,549
			443,205			457,084			447,370
Total regulatory liabilities			$	503,277		$	518,474		$	490,305
Net regulatory position			$	(99,882	)	$	(124,861	)	$	(72,908	)

* Estimated recovery period for regulatory assets currently being recovered in rates charged to customers.

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

Regulatory Liabilities

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

	Estimated Recovery Period as of March 31, 2020	*	March 31, 2020			March 31, 2019			December 31, 2019
			(In thousands)
Regulatory assets:
Current:
Natural gas costs recoverable through rate adjustments	Up to 1 year		$	39,805		$	61,236		$	42,823
Cost recovery mechanisms	Up to 1 year		6,686			6,661			6,288
Conservation programs	Up to 1 year		6,303			5,613			6,963
Other	Up to 1 year		2,412			984			7,539
			55,206			74,494			63,613
Noncurrent:
Pension and postretirement benefits	**		157,051			165,879			157,069
Asset retirement obligations	Over plant lives		67,475			63,633			66,000
Plant to be retired	-		41,080			6,691			32,931
Natural gas costs recoverable through rate adjustments	Up to 3 years		33,027			30,229			46,381
Manufactured gas plant site remediation	-		15,699			17,064			15,126
Cost recovery mechanisms	Up to 10 years		11,891			11,174			13,108
Taxes recoverable from customers	Over plant lives		11,082			11,858			11,486
Long-term debt refinancing costs	Up to 17 years		4,133			4,746			4,286
Costs related to identifying generation development	Up to 7 years		1,937			2,394			2,052
Other	Up to 19 years		4,814			5,451			5,345
			348,189			319,119			353,784
Total regulatory assets			$	403,395		$	393,613		$	417,397
Regulatory liabilities:
Current:
Natural gas costs refundable through rate adjustments			$	32,181		$	29,739		$	23,825
Taxes refundable to customers			4,002			8,139			3,472
Other			23,889			23,512			15,638
			60,072			61,390			42,935
Noncurrent:
Taxes refundable to customers			240,148			259,638			246,034
Plant removal and decommissioning costs			174,120			172,569			173,722
Pension and postretirement benefits			18,040			15,239			18,065
Other			10,897			9,638			9,549
			443,205			457,084			447,370
Total regulatory liabilities			$	503,277		$	518,474		$	490,305
Net regulatory position			$	(99,882	)	$	(124,861	)	$	(72,908	)

* Estimated recovery period for regulatory assets currently being recovered in rates charged to customers.

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