Note 7 - Fair Value Measurements - Schedule of Carrying Value of Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Apr. 02, 2015
IRU Assets			$ 2,304
IRU Obligations			$ 4,153
Reported Value Measurement [Member]
IRU Assets	$ 2,025	$ 2,118
IRU Obligations	$ 3,594	$ 3,747