Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Accounts Receivable, Allowance for Credit Loss, Current	$ 11		$ 11
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.001		$ 0.001
Preferred Stock, Shares Authorized (in shares)	25,000,000		25,000,000
Preferred Stock, Shares Issued (in shares)	0		0
Preferred Stock, Shares Outstanding (in shares)	0		0
Common Stock, Par or Stated Value Per Share (in dollars per share)		$ 0.001	$ 0.001
Common Stock, Shares Authorized (in shares)	100,000,000		100,000,000
Common Stock, Shares, Outstanding (in shares)	21,586,150		20,076,773
Common Stock, Shares, Issued (in shares)	21,586,150		20,076,773