Consolidated Statements of Revenues and Expenses (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating revenues:
Total operating revenues	$ 420,442	$ 376,331
Operating expenses:
Fuel	165,484	108,065
Production	95,780	105,373
Depreciation and amortization	70,926	67,619
Purchased power	16,875	16,920
Accretion	13,532	13,781
Total operating expenses	362,597	311,758
Operating margin	57,845	64,573
Other income:
Investment income	11,847	11,960
Other	3,030	2,171
Total other income	14,877	14,131
Interest charges:
Interest expense	104,669	103,479
Allowance for debt funds used during construction	(56,773)	(53,639)
Amortization of debt discount and expense	2,846	2,906
Net interest charges	50,742	52,746
Net margin	21,980	25,958
Members
Operating revenues:
Total operating revenues	417,449	376,272
Non-Members
Operating revenues:
Total operating revenues	$ 2,993	$ 59