Utility Plant (Schedule Of Major Classes Of Utilty Plant) (Details) (USD $)	Dec. 31, 2012		Dec. 31, 2011
Public Utility, Property, Plant and Equipment [Line Items]
Total electric plant in service	$ 891,781,509		$ 862,362,243
Construction work in progress	263,459,794	[1]	206,005,783	[1]
Total utility plant	1,155,241,303		1,068,368,026
Steam Production Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Generation and processing	60,462,671		60,462,671
Hydraulic Production Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Generation and processing	20,513,746		20,456,395
Other Production Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Generation and processing	127,980,607		134,434,574
Transmission Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Transmission	252,910,740		252,561,598
Distribution Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Distribution	257,587,220		257,341,532
General Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Other property, plant and equipment	51,901,426		45,144,425
Unclassified Electric Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Other property, plant and equipment	109,023,464	[2]	80,559,413	[2]
Intangible Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Transmission	4,710,912	[2]	4,710,912	[2]
Other [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Other- land	6,690,723		6,690,723
Southcentral Power Project [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Construction work in progress	$ 245,500,000		$ 177,400,000

[1] The amount associated with the construction of SPP included in construction work in progress was $245.5 million and $177.4 million at December 31, 2012 and 2011, respectively.

[2] Unclassified electric plant in service consists of complete unclassified general plant, generation plant, transmission plant and distribution plant. Depreciation of unclassified electric plant in service has been included in functional plant depreciation accounts in accordance with the anticipated eventual classification of the plant investment. Intangible plant represents Chugach's share of a Bradley Lake transmission line financed internally. Other represents Electric Plant Held for Future Use