Note 4 - Recent Accounting Pronouncements - Consolidated Statement of Financial Condition (Details) - USD ($) $ in Thousands	3 Months Ended					6 Months Ended		12 Months Ended
	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2019	Jul. 01, 2019
Operating leases, Right-of-Use Assets	$ 5,507					$ 5,507			$ 6,149
Current portion of operating lease obligations	2,027					2,027			1,798
Operating long-term lease obligations	3,544					3,544			4,351
Cost of goods sold	38,228			$ 37,984		72,639	$ 73,226
Selling, general and administrative	15,874			15,100		32,132	30,823
Other income (expense) net	$ (887)			(457)		$ (1,056)	$ (451)
Accounting Standards Update 2016-02 [Member]
Operating leases, Right-of-Use Assets									6,149
Current portion of operating lease obligations									1,798
Operating long-term lease obligations									$ 4,351
Accounting Standards Update 2017-07 [Member] | Restatement Adjustment [Member]
Cost of goods sold		329	$ 127	127	$ 127			710
Selling, general and administrative		97	41	41	41			220
Other income (expense) net		$ (426)	$ (168)	$ (168)	$ (168)			$ (930)