Utility Plant (Details) - USD ($)		Dec. 31, 2016	Dec. 31, 2015
Public Utility, Property, Plant and Equipment [Line Items]
Other property, plant and equipment		$ 1,192,513,869	$ 1,128,474,292
Electric plant in service		1,192,513,869	1,128,474,292
Construction work in progress		18,455,940	15,601,374
Total utility plant		1,210,969,809	1,144,075,666
Steam Production Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Generation and processing		101,116,277	100,938,247
Hydroelectric Production Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Generation and processing		33,659,129	20,591,678
Other Production Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Generation and processing		287,404,484	284,035,865
Transmission Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Transmission		282,040,969	277,490,606
Distribution Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Distribution		294,641,485	290,680,919
General Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Other property, plant and equipment		54,982,432	51,841,582
Electric plant in service		54,982,432	51,841,582
Unclassified Electric Plant In Service [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Other property, plant and equipment	[1]	83,457,981	95,611,615
Electric plant in service	[1]	83,457,981	95,611,615
Intangible Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Transmission	[1]	5,455,371	5,455,371
Beluga River Unit [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Other property, plant and equipment		47,927,331	0
Electric plant in service		47,927,331	0
Other [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Other- land	[1]	$ 1,828,409	$ 1,828,409

[1] 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.