Leases - Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating Leased Assets [Line Items]
Operating Lease Cost - Purchased Power & Energy Storage Lease Contracts	$ 86,276	$ 73,170	$ 131,505	$ 111,451
Variable lease, cost	48,572	42,188	113,296	103,493
Short-term lease cost	9,114	5,065	17,918	8,568
Purchased Power Lease Contracts
Operating Leased Assets [Line Items]
Operating Lease Cost - Purchased Power & Energy Storage Lease Contracts	81,456	68,714	117,111	97,854
Land, Property and Equipment Leases
Operating Leased Assets [Line Items]
Operating Lease Cost - Purchased Power & Energy Storage Lease Contracts	4,820	4,456	14,394	13,597
Total lease cost	$ 143,962	$ 120,423	$ 262,719	$ 223,512