Note 1 - Summary of Significant Accounting Policies (Details Textual)	12 Months Ended
	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) shares	Dec. 31, 2019 USD ($) shares
Incremental Costs of Obtaining a Contract, Deferred During Period	$ 1,900,000	$ 3,700,000	$ 3,600,000
Capitalized Contract Cost, Net, Noncurrent	3,772,000	4,555,000
Capitalized Contract Cost, Impairment Loss	31,000	63,000	22,000
Capitalized Computer Software, Additions	2,800,000	2,700,000
Asset Impairment Charges, Total	0	0	0
Impairment of Intangible Assets (Excluding Goodwill), Total	0	0	0
Goodwill, Impairment Loss	$ 0	714,000
Number of Operating Segments	1
Number of Reporting Units	1
Income Tax Credits and Adjustments	$ 10,000	45,000	$ 24,000
Cash Equivalents, at Carrying Value, Total	6,300,000	5,000,000.0
Operating Lease, Impairment Loss	324,000
Excess Loss Coverage Per Person	150,000
Claims Loss Coverage, Minimum Aggregate Deductible	3,200,000	2,800,000
Self Insurance Reserve, Current	$ 406,000	$ 418,000
Common Class A [Member]
Stock Options Excluded from Computation of Earnings Per Share, Amount (in shares) | shares	127,185	65,127	16,221
Cyber Attack [Member] | Recoveries Received Direct by the Company [Member]
Proceeds from Insurance Settlement, Operating Activities		$ 3,300,000
Cyber Attack [Member] | Recoveries Paid Directly by Insurer to Outside Vendor [Member]
Proceeds from Insurance Settlement, Operating Activities		447,000
Cyber Attack [Member] | Reimbursement for Lost Revenue [Member]
Insurance Recoveries		533,000
Property Damage Excluding Cyber Attack [Member] | Other Income [Member]
Insurance Recoveries		260,000
Canadian Subsidiary [Member]
Goodwill, Impairment Loss	$ 714,000	$ 714,000
Number of Customers	1
Minimum [Member]
Capitalized Contract Cost, Amortization Period (Year)	3 years
Minimum [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Minimum [Member] | Computer Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	3 years
Minimum [Member] | Software and Software Development Costs [Member]
Property, Plant and Equipment, Useful Life (Year)	1 year
Minimum [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment, Useful Life (Year)	7 years
Maximum [Member]
Capitalized Contract Cost, Amortization Period (Year)	5 years
Maximum [Member] | Furniture and Fixtures [Member]
Property, Plant and Equipment, Useful Life (Year)	10 years
Maximum [Member] | Computer Equipment [Member]
Property, Plant and Equipment, Useful Life (Year)	5 years
Maximum [Member] | Software and Software Development Costs [Member]
Property, Plant and Equipment, Useful Life (Year)	5 years
Maximum [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment, Useful Life (Year)	40 years