Note 2 - Summary of Significant Accounting Policies (Details Textual) £ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2021 GBP (£)
Contract with Customer, Asset, after Allowance for Credit Loss, Current, Total	$ 800	$ 200
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease), Total	1,600
Accounts Receivable, Credit Loss Expense (Reversal)	168	173
Cash, FDIC Insured Amount	250
Cash, Uninsured Amount	5,800
Cash, FSCS Insured Amount	100		£ 75
Cash, Uninsured Amount, FSCS	3,400
Advertising Expense	$ 11	$ 11
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)	2 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)	7 years