Note 5 - Cash, Cash Equivalents and Restricted Cash (Details Textual) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2022	Dec. 31, 2021
Average Reserve Balances Required to be Maintained with Federal Bank	$ 0	$ 0
Average Excess Balances Maintained With Federal Reserve Bank	1,400,000	1,600,000
Margin Deposit Assets	0	24,300
Restricted Cash, Total	34,900	690
Bank [Member]
Restricted Cash, Total	$ 0	$ 5,900

Amount of average balances maintained with Federal Reserve Bank in excess of the average balances required.

No definition available.

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- Definition

Average reserve balances required to be maintained with federal bank.

+ References

No definition available.

+ Details

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- Definition

The amount of cash or securities placed with a broker or counterparty as security for a trading or derivatives securities position which was partially obtained with funds provided by the broker dealer.

+ References

+ Details

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- Definition

Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(1))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=126999549&loc=SL98516268-108586

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(1)(a))
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(2))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

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- Details

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