Note 1 - Organization and Significant Accounting Policies - Revenues by Product Line (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018
Total revenue	$ 6,604	$ 6,701	$ 5,770	$ 5,293	$ 5,178	$ 3,815	$ 12,471	$ 8,993	$ 19,075	$ 14,286	$ 27,371	$ 19,742
Biopreservation Media [Member]
Total revenue											23,358	19,742
Automated Thawing Products [Member]
Total revenue											1,184
Evo Shippers [Member]
Total revenue											692
Freezers and Accessories [Member]
Total revenue											$ 2,137