Note 1 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018	Mar. 13, 2017
Operating Lease, Right-of-Use Asset		$ 80,458	$ 80,458
Operating Lease, Liability, Total		79,840	$ 79,840
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset				$ 82,020
Operating Lease, Liability, Total				$ 82,020
The 2017 Share Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount						$ 10,000
Treasury Stock, Shares, Acquired			118,825
Treasury Stock Acquired, Average Cost Per Share			$ 1.72
Treasury Stock, Value, Acquired, Cost Method			$ 205
Chief Executive Officer [Member]
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits		$ 1,595
Chief Executive Officer [Member] | Subsequent Event [Member]
Payments for Postemployment Benefits	$ 1,267
ACS Cable Systems LLC and Quintillion Holdings, LLC Joint Venture [Member]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage			50.00%