Note 4 - Fair Value Measurements - Changes in Level 3 Assets Measured at Fair Value (Details) $ in Thousands	3 Months Ended
Mar. 31, 2019 USD ($)
Balance
Fair value at recognition date	67,136
Accrued interest	328
Unrealized loss on investments, recognized in OCI	(1,055)
Balance	66,409
CLO Junior Subordinated Notes [Member]
Balance
Fair value at recognition date	54,279
Accrued interest	294
Unrealized loss on investments, recognized in OCI	(1,055)
Balance	53,518
CLO Senior Subordinated Notes [Member]
Balance
Fair value at recognition date	9,289
Accrued interest	34
Unrealized loss on investments, recognized in OCI
Balance	9,323
Equity Securities [Member]
Balance
Fair value at recognition date	3,568
Accrued interest
Unrealized loss on investments, recognized in OCI
Balance	$ 3,568

Amount of accrued interest of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

No definition available.

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- Definition

Amount of gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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