Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2016
Significant Accounting Policies [Abstract]
Management Estimates	a. Management Estimates In preparing the financial statements in conformity with U.S. GAAP, the management of Chugach is required to make estimates and assumptions relating to the reporting of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the balance sheet and revenues and expenses for the reporting period. Estimates include allowance for doubtful accounts, workers’ compensation liability, deferred charges and credits, unbilled revenue, estimated useful life of utility plant, cost of removal and asset retirement obligation (ARO), purchase price allocation for Beluga River Unit (BRU), and remaining proved BRU reserves. Actual results could differ from those estimates.
Full Cost Method	b. Full Cost Method Pursuant to Accounting Standards Codification (ASC) 932-360-25, “Extractive Activities-Oil and Gas – Property, Plant and Equipment – Recognition”, Chugach has elected the Full Cost method, rather than the Successful Efforts method, to account for exploration and development costs of gas reserves. This is the first time Chugach has invested in oil or gas activities, so there is no prior policy of using the Successful Efforts method.
Depreciation, Depletion And Amortization (DD&A)	c. Depreciation, Depletion and Amortization (DD&A) Chugach records DD&A expense on the BRU assets based on units of production using the following formula: ten percent of the total production from the BRU as provided by the operator divided by ten percent of the estimated remaining proved reserves (in Mcf) in the field multiplied by Chugach’s total assets in the BRU.
Asset Retirement Obligation (ARO)	d. Asset Retirement Obligation (ARO) Chugach calculated and recorded an Asset Retirement Obligation associated with the BRU. Chugach uses its BRU financing rate as its credit adjusted risk free rate and the expected cash flow approach to calculate the fair value of the ARO liability. The ARO asset is depreciated using the DD&A formula outlined above. The ARO liability is accreted using the interest method of allocation.
Regulation	e. Regulation The accounting records of Chugach conform to the Uniform System of Accounts as prescribed by the Federal Energy Regulatory Commission (FERC). Chugach meets the criteria, and accordingly, follows the accounting and reporting requirements of Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 980, “Topic 980 - Regulated Operations.” FASB ASC 980 provides for the recognition of regulatory assets and liabilities as allowed by regulators for costs or credits that are reflected in current rates or are considered probable of being included in future rates. Chugach’s regulated rates are established to recover all of the specific costs of providing electric service. In each rate filing, rates are set at levels to recover all of the specific allowable costs and those rates are then collected from retail and wholesale customers. The regulatory assets or liabilities are then reduced as the cost or credit is reflected in earnings and rates.
Income Taxes	f. Income Taxes Chugach is exempt from federal income taxes under the provisions of Section 501(c)(12) of the Internal Revenue Code and for the six month periods ended June 30, 2016 and 2015 was in compliance with that provision. Chugach applies a more-likely-than-not recognition threshold for all tax uncertainties. FASB ASC 740, “Topic 740 – Income Taxes,” only allows the recognition of those tax benefits that have a greater than 50 percent likelihood of being sustained upon examination by the taxing authorities. Chugach’s management reviewed Chugach’s tax positions and determined there were no outstanding or retroactive tax positions that were not highly certain of being sustained upon examination by the taxing authorities.
Restricted Cash Equivalents	g. Restricted Cash Equivalents Restricted cash equivalents include funds on deposit for future workers’ compensation claims, which amounted to $2.8 million at June 30, 2016, and December 31, 2015.
Accounts Receivable	h. Accounts Receivable Included in accounts receivable are invoiced amounts to ML&P for their proportionate share of current Southcentral Power Project (SPP) costs, which amounted to $1.1 million at June 30, 2016, and December 31, 2015. In addition, accounts receivable includes invoiced amounts for grants to support the construction of facilities to divert water and safely transmit electricity, which amounted to $0.2 million at December 31, 2015. At June 30, 2016, accounts receivable also includes $0.3 million from BRU operations primarily associated with gas sales to ENSTAR.
Fuel Stock	i. Fuel Stock Fuel Stock is the weighted average cost of fuel injected into the Cook Inlet Natural Gas Storage Alaska (CINGSA). Chugach’s fuel balance in storage amounted to $7.4 million and $7.1 million at June 30, 2016, and December 31, 2015, respectively.
Corrections	h. Corrections For the period ended June 30, 2016, Chugach recorded the following correction for the period ended June 30, 2015: A correction representing the cash received from customers for the undergrounding ordinance, included in net receipts on consumer advances for construction, previously reported as other current liabilities. The impact of this correction was a decrease in cash provided by operating activities and cash used in financing activities of $1.7 million for the six months ended June 30, 2015.

Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2016

Significant Accounting Policies [Abstract]

a. Management Estimates

In preparing the financial statements in conformity with U.S. GAAP, the management of Chugach is required to make estimates and assumptions relating to the reporting of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the balance sheet and revenues and expenses for the reporting period. Estimates include allowance for doubtful accounts, workers’ compensation liability, deferred charges and credits, unbilled revenue, estimated useful life of utility plant, cost of removal and asset retirement obligation (ARO), purchase price allocation for Beluga River Unit (BRU), and remaining proved BRU reserves. Actual results could differ from those estimates.

Full Cost Method

b. Full Cost Method

Pursuant to Accounting Standards Codification (ASC) 932-360-25, “Extractive Activities-Oil and Gas – Property, Plant and Equipment – Recognition”, Chugach has elected the Full Cost method, rather than the Successful Efforts method, to account for exploration and development costs of gas reserves. This is the first time Chugach has invested in oil or gas activities, so there is no prior policy of using the Successful Efforts method.

Depreciation, Depletion And Amortization (DD&A)

c. Depreciation, Depletion and Amortization (DD&A)

Chugach records DD&A expense on the BRU assets based on units of production using the following formula: ten percent of the total production from the BRU as provided by the operator divided by ten percent of the estimated remaining proved reserves (in Mcf) in the field multiplied by Chugach’s total assets in the BRU.

Asset Retirement Obligation (ARO)

d. Asset Retirement Obligation (ARO)

Chugach calculated and recorded an Asset Retirement Obligation associated with the BRU. Chugach uses its BRU financing rate as its credit adjusted risk free rate and the expected cash flow approach to calculate the fair value of the ARO liability. The ARO asset is depreciated using the DD&A formula outlined above. The ARO liability is accreted using the interest method of allocation.

Regulation

e. Regulation

The accounting records of Chugach conform to the Uniform System of Accounts as prescribed by the Federal Energy Regulatory Commission (FERC). Chugach meets the criteria, and accordingly, follows the accounting and reporting requirements of Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 980, “Topic 980 - Regulated Operations.” FASB ASC 980 provides for the recognition of regulatory assets and liabilities as allowed by regulators for costs or credits that are reflected in current rates or are considered probable of being included in future rates. Chugach’s regulated rates are established to recover all of the specific costs of providing electric service. In each rate filing, rates are set at levels to recover all of the specific allowable costs and those rates are then collected from retail and wholesale customers. The regulatory assets or liabilities are then reduced as the cost or credit is reflected in earnings and rates.

Income Taxes

f. Income Taxes

Chugach is exempt from federal income taxes under the provisions of Section 501(c)(12) of the Internal Revenue Code and for the six month periods ended June 30, 2016 and 2015 was in compliance with that provision.

Chugach applies a more-likely-than-not recognition threshold for all tax uncertainties. FASB ASC 740, “Topic 740 – Income Taxes,” only allows the recognition of those tax benefits that have a greater than 50 percent likelihood of being sustained upon examination by the taxing authorities. Chugach’s management reviewed Chugach’s tax positions and determined there were no outstanding or retroactive tax positions that were not highly certain of being sustained upon examination by the taxing authorities.

Restricted Cash Equivalents

g. Restricted Cash Equivalents

Restricted cash equivalents include funds on deposit for future workers’ compensation claims, which amounted to $2.8 million at June 30, 2016, and December 31, 2015.

Accounts Receivable

h. Accounts Receivable

Included in accounts receivable are invoiced amounts to ML&P for their proportionate share of current Southcentral Power Project (SPP) costs, which amounted to $1.1 million at June 30, 2016, and December 31, 2015. In addition, accounts receivable includes invoiced amounts for grants to support the construction of facilities to divert water and safely transmit electricity, which amounted to $0.2 million at December 31, 2015. At June 30, 2016, accounts receivable also includes $0.3 million from BRU operations primarily associated with gas sales to ENSTAR.

Fuel Stock

i. Fuel Stock

Fuel Stock is the weighted average cost of fuel injected into the Cook Inlet Natural Gas Storage Alaska (CINGSA). Chugach’s fuel balance in storage amounted to $7.4 million and $7.1 million at June 30, 2016, and December 31, 2015, respectively.

Corrections

h. Corrections

For the period ended June 30, 2016, Chugach recorded the following correction for the period ended June 30, 2015:

A correction representing the cash received from customers for the undergrounding ordinance, included in net receipts on consumer advances for construction, previously reported as other current liabilities. The impact of this correction was a decrease in cash provided by operating activities and cash used in financing activities of $1.7 million for the six months ended June 30, 2015.