Note 3 - Investments and Fair Value Measurements - Reconciliation of Changes in Fair Value (Details) - Fair Value, Inputs, Level 3 [Member] - Investment in Convertible Note Receivable [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Balance, liabilities	$ 655
Conversion to common stock of VPS	(655)
Balance, liabilities