Long-Term Debt and Capital Leases Long-Term Debt and Capital Leases (Schedule of Capital Lease Obligation Maturities) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Capital Lease Obligations Principal	$ 65,435	$ 68,601
Alaska Electric Light & Power [Member] | Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Capital Lease Obligations Principal Year 1	2,415
Capital Leases Obligations Principal Year 2	2,535
Capital Leases Obligations Principal Year 3	2,660
Capital Leases Obligations Principal Year 4	2,800
Capital Leases Obligations Principal Year 5	2,935
Capital Leases Obligations Principal Thereafter	48,815
Capital Lease Obligations Principal	62,160
Capital Lease Obligations Interest Year 1	3,042
Capital Leases Obligations Interest Year 2	2,921
Capital Leases Obligations Interest Year 3	2,795
Capital Leases Obligations Interest Year 4	2,662
Capital Leases Obligations Interest Year 5	2,522
Capital Leases Obligations Interest Thereafter	16,674
Capital Leases Obligations Interest	30,616
Capital Leases, Future Minimum Payments, Remainder of Fiscal Year	5,457
Capital Leases, Future Minimum Payments Due in Two Years	5,456
Capital Leases, Future Minimum Payments Due in Three Years	5,455
Capital Leases, Future Minimum Payments Due in Four Years	5,462
Capital Leases, Future Minimum Payments Due in Five Years	5,457
Capital Leases, Future Minimum Payments Due Thereafter	65,489
Capital Leases, Future Minimum Payments Due	$ 92,776