Leases (Tables)

3 Months Ended

Mar. 31, 2024

Leases [Abstract]

Schedule of balance sheet impact of leases

We combine lease and nonlease components for all lease agreements.

Classification	March 31, 2024		December 31, 2023
	(dollars in thousands)
Right-of-use assets—Finance leases
Right-of-use assets	$	302,732	$	302,732
Less: Accumulated provision for depreciation	(279,465)		(278,586)
Total finance lease assets	$	23,267	$	24,146
Lease liabilities—Finance leases
Obligations under finance leases	$	43,586	$	43,586
Long-term debt and finance leases due within one year	9,351		9,351
Total finance lease liabilities	$	52,937	$	52,937

Classification	March 31, 2024		December 31, 2023
	(dollars in thousands)
Right-of-use assets—Operating leases
Electric plant in service, net	$	6,181	$	6,587
Total operating lease assets	$	6,181	$	6,587
Lease liabilities—Operating leases
Capitalization—Other	$	4,786	$	5,152
Other current liabilities	1,395		1,529
Total operating lease liabilities	$	6,181	$	6,681

Schedule of lease cost

		Three months ended
Lease Cost	Classification	March 31, 2024		March 31, 2023
		(dollars in thousands)
Finance lease cost:
Amortization of leased assets	Depreciation and amortization	$	2,338	$	2,099
Interest on lease liabilities	Interest expense	1,400		1,638
Operating lease cost:	Inventory(1) & production expense	538		329
Total leased cost		$	4,276	$	4,066

(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, 2024		December 31, 2023
Lease Term and Discount Rate:
Weighted-average remaining lease term (in years)
Finance leases	5.01		5.26
Operating leases	5.70		5.77
Weighted-average discount rate:
Finance leases	11.05	%	11.05	%
Operating leases	6.45	%	6.37	%

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

	Three months ended March 31,
	2024		2023
	(dollars in thousands)
Other Information:
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$	632	$	409
Right-of-use assets obtained in exchange for new operating lease liabilities	$	17	$	—

Schedule of maturities of finance lease liabilities

Maturity analysis of our finance and operating lease liabilities as of March 31, 2024 is as follows:

	(dollars in thousands)
Year Ending December 31,	Finance Leases		Operating Leases		Total
2024	$	14,949	$	1,334	$	16,283
2025	14,949		1,708		16,657
2026	14,949		1,416		16,365
2027	14,949		1,139		16,088
2028	3,052		1,029		4,081
Thereafter	7,633		723		8,356
Total lease payments	$	70,481	$	7,349	$	77,830
Less: imputed interest	(17,544)		(1,168)		(18,712)
Present value of lease liabilities	$	52,937	$	6,181	$	59,118

Schedule of maturities of operating lease liabilities

Maturity analysis of our finance and operating lease liabilities as of March 31, 2024 is as follows:

	(dollars in thousands)
Year Ending December 31,	Finance Leases		Operating Leases		Total
2024	$	14,949	$	1,334	$	16,283
2025	14,949		1,708		16,657
2026	14,949		1,416		16,365
2027	14,949		1,139		16,088
2028	3,052		1,029		4,081
Thereafter	7,633		723		8,356
Total lease payments	$	70,481	$	7,349	$	77,830
Less: imputed interest	(17,544)		(1,168)		(18,712)
Present value of lease liabilities	$	52,937	$	6,181	$	59,118

Schedule of lease income

Lease income recognized during the three months ended March 31, 2024 and 2023 was as follows:

	Three Months Ended March 31,
	2024		2023
	(dollars in thousands)
Lease income	$	1,387	$	1,685