Note 5 - Acquisition (Details Textual) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended	12 Months Ended	21 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2021	Dec. 01, 2020
Goodwill, Purchase Accounting Adjustments				$ (18,788)
Goodwill, Ending Balance	$ 102,342			102,342	$ 121,130	$ 102,342
PWI Holdings [Member]
Business Acquisition, Percentage of Voting Interests Acquired			100.00%
Payments to Acquire Businesses, Gross			$ 24,400
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred			100
Goodwill, Purchase Accounting Adjustments	(18,800)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill, Total	19,600			19,600		19,600
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Service Fees	(3,600)
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Tax Liabilities	4,200
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Accrued Expenses and Other Liabilities	100
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Working Capital True-up	100
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Amortization Expense and Accumulated Amortization	600	$ 600	600		100	1,900
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Service Fee and Commission Revenue	(400)	$ (500)	$ (700)		$ (300)	(1,900)
Goodwill, Ending Balance	20,200			20,200		20,200	$ 20,238
PWI Holdings [Member] | Customer Relationships [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill, Total	15,000			15,000		15,000
PWI Holdings [Member] | Trade Names [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill, Total	$ 4,600			$ 4,600		$ 4,600