Note 2 - Summary of Significant Accounting Policies (Details Textual) £ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2020 GBP (£)
Contract with Customer, Asset, after Allowance for Credit Loss, Current, Total	$ 100	$ 2,100
Accounts Receivable, Allowance for Credit Loss, Period Increase (Decrease), Total	1,600
Accounts Receivable, Credit Loss Expense (Reversal)	173	11
Cash, FDIC Insured Amount	250
Cash, Uninsured Amount	2,400
Cash, FSCS Insured Amount	100		£ 75
Cash, Uninsured Amount, FSCS	2,700
Advertising Expense	$ 11	$ 35
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)	2 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)	7 years