Note 3 - Joint Venture (Details Textual) - USD ($) $ in Thousands		12 Months Ended
	Apr. 02, 2015	Dec. 31, 2019
Variable Interest Entity, Initial Consolidation, Gain (Loss)	$ 0
ACS Cable Systems LLC and Quintillion Holdings, LLC Joint Venture [Member]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage		50.00%
ACS Cable Systems LLC and Quintillion Holdings, LLC Joint Venture [Member] | Quintillion Holdings, LLC [Member]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage		50.00%