Note 19 - Business Segments - Service and Product Revenues From External Customers (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenues	$ 231,694	$ 232,468
Business and Wholesale Revenue [Member]
Revenues	150,564	144,594
Business and Wholesale Revenue [Member] | Business Broadband [Member]
Revenues	61,785	60,934
Business and Wholesale Revenue [Member] | Business Voice and Other [Member]
Revenues	28,660	28,429
Business and Wholesale Revenue [Member] | Managed IT Services [Member]
Revenues	6,494	5,742
Business and Wholesale Revenue [Member] | Equipment Sales and Installations [Member]
Revenues	4,698	5,127
Business and Wholesale Revenue [Member] | Wholesale Broadband [Member]
Revenues	43,310	38,362
Business and Wholesale Revenue [Member] | Wholesale Voice and Other [Member]
Revenues	5,617	6,000
Consumer Revenue [Member]
Revenues	37,020	37,302
Consumer Revenue [Member] | Broadband [Member]
Revenues	26,589	26,144
Consumer Revenue [Member] | Voice and Other [Member]
Revenues	10,431	11,158
Business, Wholesale and Consumer Revenue [Member]
Revenues	187,584	181,896
Regulatory Revenue [Member]
Revenues	44,110	50,572
Regulatory Revenue [Member] | Access [Member]
Revenues	24,416	30,878
Regulatory Revenue [Member] | High Cost Support [Member]
Revenues	$ 19,694	$ 19,694