Note 1 - Organization and Nature of Operations (Details Textual) $ / shares in Units, $ in Millions		12 Months Ended
Sep. 01, 2017 $ / shares	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 $ / shares	Aug. 31, 2017 $ / shares
Stockholders' Equity Note, Stock Split, Conversion Ratio	10
Common Stock, Par or Stated Value Per Share (in dollars per share) \| $ / shares	$ 0.01	$ 0.01	$ 0.01	$ 0.001
Assets under Management, Carrying Amount		$ 2,770
Number of Operating Segments		3
Collateralized Debt Obligations [Member]
Assets under Management, Carrying Amount		$ 2,060

The carrying amount of assets an investment adviser manages on behalf of investors.

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- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8672-108599

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- Definition

Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 4
-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187143-122770

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