Consolidated Statements Of Revenues, Expenses, And Patronage Capital - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Operating Revenues	$ 1,082,391	$ 1,005,917	$ 780,640
Type of Revenue [Extensible List]	us-gaap:ElectricityMember	us-gaap:ElectricityMember	us-gaap:ElectricityMember
Operating Expenses:
Fuel	$ 193,081	$ 193,599	$ 166,517
Purchased power	312,833	462,526	234,471
Transmission	173,492	151,778	131,290
Deferred energy	114,538	(78,831)	(28,116)
Operations and maintenance	95,165	91,360	78,294
Administrative and general	41,841	42,111	41,372
Depreciation and amortization	69,573	69,167	70,416
Amortization of regulatory asset/(liability), net	2,080	(960)	16,458
Accretion of asset retirement obligations	6,077	5,873	5,664
Taxes, other than income taxes	8,614	8,784	9,171
Total Operating Expenses	1,017,294	945,407	725,537
Operating Margin	65,097	60,510	55,103
Other income (expense), net	(284)	1,967	409
Investment income	9,472	4,709	20,162
Interest charges, net	(61,332)	(55,265)	(55,657)
Income taxes (expense)/benefit	(110)	(151)	8
Net Margin including Non-controlling interest	12,843	11,770	20,025
Non-controlling interest	(290)	(465)	22
Net Margin attributable to ODEC	12,553	11,305	20,047
Patronage Capital - Beginning of Period	476,082	464,777	453,470
Patronage Capital - Retirement			(8,740)
Patronage Capital - End of Period	$ 488,635	$ 476,082	$ 464,777