Consolidated Statements Of Revenues, Expenses, And Patronage Capital - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Operating Revenues	$ 877,871		$ 1,020,028	$ 951,576
Operating Expenses:
Fuel	138,391		159,917	213,528
Purchased power	408,006		494,909	518,814
Transmission	121,456		113,622	75,959
Deferred energy	12,194		47,783	(57,141)
Operations and maintenance	50,088		49,768	49,599
Administrative and general	41,477		37,448	40,279
Depreciation and amortization	45,739		45,168	42,049
Amortization of regulatory asset/(liability), net	2,233		9,496	5,838
Accretion of asset retirement obligations	4,839		4,695	3,870
Taxes, other than income taxes	8,256		8,269	8,256
Total Operating Expenses	832,679		971,075	901,051
Operating Margin	45,192		48,953	50,525
Other expense, net	(3,811)		(3,339)	(3,086)
Investment income	5,411		5,519	7,349
Interest income on North Anna Unit 3 cost recovery			6,393	0
Interest charges, net	(29,133)		(45,627)	(45,693)
Income taxes	(1)		(3)	1
Net Margin including Non-controlling interest	17,658		11,896	9,096
Non-controlling interest	(21)		(17)	4
Net Margin attributable to ODEC	17,637	[1]	11,879	9,100
Patronage Capital - Beginning of Period	390,976		379,097	369,997
Patronage Capital - Retirement	(5,756)
Patronage Capital - End of Period	$ 402,857		$ 390,976	$ 379,097

[1] For the fourth quarter of 2016, includes an equity contribution of $5.8 million.