Leases (Tables)

3 Months Ended

Mar. 31, 2023

Leases [Abstract]

Schedule of balance sheet impact of leases

For lease agreements entered into or reassessed after the adoption of the new leases standard, we combine lease and nonlease components.

Classification	March 31, 2023		December 31, 2022
	(dollars in thousands)
Right-of-use assets—Finance leases
Right-of-use assets	$	302,732	$	302,732
Less: Accumulated provision for depreciation	(274,194)		(272,876)
Total finance lease assets	$	28,538	$	29,856
Lease liabilities—Finance leases
Obligations under finance leases	$	52,937	$	52,937
Long-term debt and finance leases due within one year	8,398		8,398
Total finance lease liabilities	$	61,335	$	61,335

Classification	March 31, 2023		December 31, 2022
	(dollars in thousands)
Right-of-use assets—Operating leases
Electric plant in service, net	$	3,032	$	3,326
Total operating lease assets	$	3,032	$	3,326
Lease liabilities—Operating leases
Capitalization—Other	$	1,961	$	2,256
Other current liabilities	1,084		1,164
Total operating lease liabilities	$	3,045	$	3,420

Schedule of lease cost

		Three months ended
Lease Cost	Classification	March 31, 2023		March 31, 2022
		(dollars in thousands)
Finance lease cost:
Amortization of leased assets	Depreciation and amortization	$	2,099	$	1,885
Interest on lease liabilities	Interest expense	1,638		1,852
Operating lease cost:	Inventory(1) & production expense	329		222
Total leased cost		$	4,066	$	3,959

(1) The majority of our operating lease costs relate to our railcar leases and such costs are added to the cost of our fossil-fuel inventories and are recognized in fuel expense as the inventories are consumed.

Summary of lease terms and discount rates

	March 31, 2023		December 31, 2022
Lease Term and Discount Rate:
Weighted-average remaining lease term (in years)
Finance leases	5.69		5.94
Operating leases	6.76		6.44
Weighted-average discount rate:
Finance leases	11.05	%	11.05	%
Operating leases	5.63	%	5.52	%

Schedule of cash paid for amounts included in the measurement of lease liabilities

	Three months ended March 31,
	2023		2022
	(dollars in thousands)
Other Information:
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$	409	$	303
Right-of-use assets obtained in exchange for new operating lease liabilities	$	—	$	—

Schedule of maturities of operating lease liabilities

Maturity analysis of our finance and operating lease liabilities as of March 31, 2023 is as follows:

	(dollars in thousands)
Year Ending December 31,	Finance Leases		Operating Leases		Total
2023	$	14,949	$	914	$	15,863
2024	14,949		850		15,799
2025	14,949		641		15,590
2026	14,949		350		15,299
2027	14,949		72		15,021
Thereafter	10,683		868		11,551
Total lease payments	$	85,428	$	3,695	$	89,123
Less: imputed interest	(24,093)		(650)		(24,743)
Present value of lease liabilities	$	61,335	$	3,045	$	64,380

Schedule of maturities of finance lease liabilities

Maturity analysis of our finance and operating lease liabilities as of March 31, 2023 is as follows:

	(dollars in thousands)
Year Ending December 31,	Finance Leases		Operating Leases		Total
2023	$	14,949	$	914	$	15,863
2024	14,949		850		15,799
2025	14,949		641		15,590
2026	14,949		350		15,299
2027	14,949		72		15,021
Thereafter	10,683		868		11,551
Total lease payments	$	85,428	$	3,695	$	89,123
Less: imputed interest	(24,093)		(650)		(24,743)
Present value of lease liabilities	$	61,335	$	3,045	$	64,380

Schedule of lessor's income from leases

Lease income recognized during the three months ended March 31, 2023 and 2022 was as follows:

	Three Months Ended March 31,
	2023		2022
	(dollars in thousands)
Lease income	$	1,685	$	1,645