Long-Term Debt Long-Term Debt (Snettisham Capital Lease Obligation) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) MW	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)
Capital Leased Assets [Line Items]
Capital Lease Obligations	$ 67,810		$ 68,601
Debt Instrument, Interest Rate, Stated Percentage	1.51%		1.29%
Alaska Electric Light & Power [Member]
Capital Leased Assets [Line Items]
Capital Leased Assets, Gross	$ 71,007		$ 71,007
Capital Leases Assets Accumulated Depreciation	6,372		5,462
Capital Leases, Income Statement, Interest Expense		$ 923
Capital Leases, Income Statement, Amortization Expense		$ 910
Alaska Electric Light & Power [Member] | Capital Lease Obligations [Member]
Capital Leased Assets [Line Items]
Capital Lease Obligations	63,881
Capital Leases Future Minimum Payments of Principal Remainder Of Fiscal Year	1,721
Capital Leases Future Minimum Payments of Principal Year Two	2,415
Capital Leases Future Minimum Payments of Principal Year Three	2,535
Capital Leases Future Minimum Payments of Principal Year Four	2,660
Capital Leases Future Minimum Payments of Principal Year Five	2,800
Capital Leases Future Minimum Payments of Principal Thereafter	51,750
Capital Leases Future Minimum Payments of Interest Remainder Of Fiscal Year	2,368
Capital Leases Future Minimum Payments of Interest Due in Two Years	3,042
Capital Leases Future Minimum Payments of Interest Due in Three Years	2,921
Capital Leases Future Minimum Payments of Interest Due in Four Years	2,795
Capital Leases Future Minimum Payments of Interest Due in Five Years	2,662
Capital Leases Future Minimum Payments of Interest Due Thereafter	19,195
Capital Leases Future Minimum Payments of Interest Due	32,983
Capital Leases, Future Minimum Payments, Remainder of Fiscal Year	4,089
Capital Leases, Future Minimum Payments Due in Two Years	5,457
Capital Leases, Future Minimum Payments Due in Three Years	5,456
Capital Leases, Future Minimum Payments Due in Four Years	5,455
Capital Leases, Future Minimum Payments Due in Five Years	5,462
Capital Leases, Future Minimum Payments Due Thereafter	70,945
Capital Leases, Future Minimum Payments Due	96,864
Alaska Electric Light & Power [Member] | Reported Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member] | Capital Lease Obligations [Member]
Capital Leased Assets [Line Items]
Capital Lease Obligations	63,881		$ 64,455
Operating Expense [Member] | Alaska Electric Light & Power [Member]
Capital Leased Assets [Line Items]
Capital Leases, Income Statement, Interest Expense	789
Capital Leases, Income Statement, Amortization Expense	$ 910
Power purchase agreement [Member] | Alaska Electric Light & Power [Member]
Capital Leased Assets [Line Items]
Evaluated Power Capacity | MW	78