Note 2 - Allowance for Credit Losses (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Details
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 0	$ 0
Ratio of bankrupt accounts to total principal loan balances	1.35%	1.48%

Amount of financing receivable 90 days or more past due and still accruing.

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-Publisher FASB
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant