Statements Of Operations (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statements Of Operations [Abstract]
Operating revenues	$ 266,971,468	$ 283,618,369	$ 258,325,345
Operating expenses:
Fuel	125,836,659	139,179,413	111,718,947
Production	16,739,931	16,853,232	18,248,656
Purchased power	22,104,687	25,861,814	26,691,968
Transmission	5,802,009	6,809,401	5,697,446
Distribution	15,822,104	13,387,477	12,216,252
Consumer accounts	6,013,419	5,465,315	5,323,551
Administrative, general and other	23,519,246	22,169,039	21,434,273
Depreciation and amortization	32,356,900	32,616,175	32,636,108
Total operating expenses	248,194,955	262,341,866	233,967,201
Interest expense:
Long-term debt and other	24,085,371	18,681,680	21,014,387
Charged to construction	(9,682,440)	(1,934,703)	(1,008,689)
Interest expense, net	14,402,931	16,746,977	20,005,698
Net operating margins	4,373,582	4,529,526	4,352,446
Nonoperating margins:
Interest income	447,434	297,983	310,964
Allowance for funds used during construction	258,301	159,916	83,966
Capital credits, patronage dividends and other	446,190	585,837	662,633
Total nonoperating margins	1,151,925	1,043,736	1,057,563
Assignable margins	$ 5,525,507	$ 5,573,262	$ 5,410,009