Leases (Tables)

12 Months Ended

Dec. 31, 2022

Leases [Abstract]

Schedule of lease costs

The following table provides information related to our lease costs (dollars in thousands):

	For the Year Ended December 31,
	2022		2021		2020
Operating Lease Cost - Purchased Power Lease Contracts	$	104,001	$	105,762	68,883
Operating Lease Cost - Land, Property, and Other Equipment	18,061		18,498		18,493
Total Operating Lease Cost	122,062		124,260		87,376
Variable lease cost (a)	122,040		118,969		122,331
Short-term lease cost	9,928		3,872		3,804
Total lease cost	$	254,030	$	247,101	$	213,511

(a)     Primarily relates to purchased power lease contracts.

The following tables provide other additional information related to operating lease liabilities (dollars in thousands):

	Year Ended December 31, 2022		Year Ended December 31, 2021		Year Ended December 31, 2020
Cash paid for amounts included in the measurement of lease liabilities — operating cash flows:	$	118,463	$	116,661	$	75,097
Right-of-use operating lease assets obtained in exchange for operating lease liabilities	16,990		500,582		441,653

	December 31, 2022		December 31, 2021
Weighted average remaining lease term	7 years		8 years
Weighted average discount rate (a)	2.21	%	2.13	%

(a)Most of our lease agreements do not contain an implicit rate that is readily determinable. For these agreements we use our incremental borrowing rate to measure the present value of lease liabilities. We determine our incremental borrowing rate at lease commencement based on the rate of interest that we would have to pay to borrow, on a collateralized basis over a similar term, an amount equal to the lease payments in a similar economic environment. We use the implicit rate when it is readily determinable.

Schedule of maturities of operating lease liabilities

The following table provides information related to the maturity of our operating lease liabilities (dollars in thousands):

	December 31, 2022
Year	Purchased Power Lease Contracts		Land, Property & Equipment Leases		Total
2023	$	106,151	$	14,254	$	120,405
2024	104,315		11,330		115,645
2025	106,582		8,655		115,237
2026	120,016		7,207		127,223
2027	89,108		5,292		94,400
Thereafter	210,486		37,873		248,359
Total lease commitments	736,658		84,611		821,269
Less imputed interest	57,682		19,130		76,812
Total lease liabilities	$	678,976	$	65,481	$	744,457