Note 15 - Income Taxes - Significant Components of Company's Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Net operating loss carry forwards	$ 16,742	$ 19,805
Deferred GCI capacity revenue	9,428	10,016
Reserves and accruals	8,947	7,910
Intangibles and goodwill	944	1,033
Pension liability	1,031	927
Allowance for doubtful accounts	1,118	775
Total deferred tax assets	38,210	40,466
Valuation allowance	(162)	(204)
Deferred tax assets after valuation allowance	38,048	40,262
Debt issuance costs		(5)
Property, plant and equipment	(37,320)	(37,287)
Fair value on interest rate swaps	(130)	(146)
Revenue contract assets	(2,407)
Other	(8)	(26)
Total deferred tax liabilities	(39,865)	(37,464)
Net deferred tax (liability) asset	$ (1,817)
Net deferred tax (liability) asset		$ 2,798