Condensed Consolidated Statements Of Revenues, Expenses, And Patronage Capital (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Operating Revenues	$ 191,117	$ 208,746
Type of Revenue [Extensible List]	us-gaap:ElectricityMember	us-gaap:ElectricityMember
Operating Expenses:
Fuel	$ 39,754	$ 42,578
Purchased power	70,992	92,890
Transmission	31,626	33,916
Deferred energy	(15,940)	(25,135)
Operations and maintenance	16,436	13,742
Administrative and general	10,880	11,856
Depreciation and amortization	17,676	17,522
Amortization of regulatory asset/(liability), net	2,487	(790)
Accretion of asset retirement obligations	1,415	1,365
Taxes, other than income taxes	2,425	2,422
Total Operating Expenses	177,751	190,366
Operating Margin	13,366	18,380
Other income (expense), net	71	(57)
Investment income	3,406	350
Interest charges, net	(14,010)	(15,537)
Income taxes	2	(3)
Net Margin including Non-controlling interest	2,835	3,133
Non-controlling interest	5	(9)
Net Margin attributable to ODEC	2,840	3,124
Patronage Capital - Beginning of Period	453,470	441,311
Patronage Capital - End of Period	$ 456,310	$ 444,435