Note 5 - Disposition of Assets (Details Textual) - USD ($)	1 Months Ended		6 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Nov. 29, 2018
Proceeds from Sale of Buildings			$ 6,350,000
Chief Technology Officer, Director, and Substantial Shareholder [Member]
Deferred Gain on Sale of Property					$ 1,400,000
Sedalia, Missouri Building [Member] | Chief Technology Officer, Director, and Substantial Shareholder [Member]
Proceeds from Sale of Buildings	$ 1,350,000
Deferred Gain on Sale of Property	$ 600,000		$ 600,000
Cable TV Business Segment [Member]
Disposal Group, Including Discontinued Operation, Consideration		$ 10,300,000
Disposal Group, Including Discontinued Operation, Consideration, Cash		3,900,000
Disposal Group, Including Discontinued Operation, Consideration, Promissory Note		$ 6,400,000
Note Receivable, Term		5 years
Note Receivable, Interest Rate		6.00%
Disposal Group, Including Discontinued Operation, Gain (Loss) on Disposal, Pretax		$ 3,300,000
Deferred Gain on Sale of Property		$ 1,300,000