Balance Sheet Components (Tables)

12 Months Ended

Dec. 31, 2023

Balance Sheet Related Disclosures [Abstract]

Schedule of Inventory

Inventories of materials and supplies, emissions allowances, stored natural gas and fuel stock are recorded at average cost and consisted of the following as of December 31 (dollars in thousands):

	2023		2022
Materials and supplies	$	81,651	$	75,766
Emission allowances		56,097		—
Stored natural gas		16,272		26,788
Fuel stock		5,964		5,120
Total	$	159,984	$	107,674

Schedule of Other Current Assets

Other current assets consisted of the following as of December 31 (dollars in thousands):

	2023		2022
Collateral posted for derivative instruments after netting with outstanding    derivative liabilities	$	—	$	66,142
Prepayments		52,752		30,201
Income taxes receivable		29,234		30,740
Derivative assets net of collateral		11,821		18,198
Other		9,977		5,886
Total	$	103,784	$	151,167

Other Property and Investments-Net and Other Non-Current Assets

Other property and investments-net and other non-current assets consisted of the following as of December 31 (dollars in thousands):

	2023		2022
Equity investments	$	153,350	$	147,809
Operating lease ROU assets		67,585		68,238
Finance lease ROU assets		36,414		40,056
Non-utility property		33,813		25,401
Notes receivable		15,287		17,954
Long-term prepaid license fees		19,448		17,936
Pension assets		32,997		13,382
Investment in affiliated trust		11,547		11,547
Deferred compensation assets		7,794		7,541
Other		15,750		15,221
Total	$	393,985	$	365,085

Other Current Liabilities

Other current liabilities consisted of the following as of December 31 (dollars in thousands):

	2023		2022
Accrued taxes other than income taxes	$	31,928	$	38,568
Employee paid time off accruals		32,072		29,279
Accrued interest		23,539		20,863
Pensions and other postretirement benefits		14,082		15,625
Derivative liabilities		17,217		26,910
Climate Commitment Act obligations		19,081		—
Deferred wholesale revenue		—		8,481
Other		54,017		49,689
Total	$	191,936	$	189,415

Schedule of Other Non-Current Liabilities and Deferred Credits

Other non-current liabilities and deferred credits consisted of the following as of December 31 (dollars in thousands):

	2023		2022
Operating lease liabilities	$	63,559	$	64,284
Finance lease liabilities		39,095		42,495
Deferred investment tax credits		28,233		28,784
Climate Commitment Act obligations		26,026		—
Asset retirement obligations		18,058		15,783
Derivative liabilities		17,902		7,892
Other		17,357		16,617
Total	$	210,230	$	175,855