Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Summary Of Significant Accounting Policies (Goodwill) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill	$ 57,672	$ 57,672
Accumulated Impairment Losses [Member]
Goodwill [Line Items]
Goodwill, Impaired, Accumulated Impairment Loss		(7,733)
Alaska Electric Light & Power [Member]
Goodwill [Line Items]
Goodwill		52,426
Corporate and Other [Member]
Goodwill [Line Items]
Goodwill		$ 12,979