Note 8 - Financial Instruments - Other Investments, at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Other investments, amortized cost	$ 21,878	$ 14,315
Other investments, carrying value	58,540	14,864
Other investments, unrealized gain (loss)	36,662	549
Other investments, at fair value	58,540	14,864
Corporate Bonds and Redeemable Preferred Stock [Member]
Other investments, amortized cost	479	479
Other investments, carrying value	476	477
Other investments, unrealized gain (loss)	(3)	(2)
Other investments, at fair value	476	477
Subordinated Notes [Member]
Other investments, amortized cost	1,485
Other investments, carrying value	1,519
Other investments, unrealized gain (loss)	34
Other investments, at fair value	1,519
Collateralized Loan Obligations [Member]
Other investments, amortized cost		2,894
Other investments, carrying value		2,522
Other investments, unrealized gain (loss)		(372)
Other investments, at fair value		2,522
U.S. Insurance JV [Member]
Other investments, amortized cost	1,168	2,048
Other investments, carrying value	1,564	2,223
Other investments, unrealized gain (loss)	396	175
Other investments, at fair value	1,564	2,223
SPAC Fund [Member]
Other investments, amortized cost	779	646
Other investments, carrying value	984	668
Other investments, unrealized gain (loss)	205	22
Other investments, at fair value	984	668
Residential Mortgage [Member]
Other investments, amortized cost	119	129
Other investments, carrying value	104	99
Other investments, unrealized gain (loss)	(15)	(30)
Other investments, at fair value	104	99
Equity Securities [Member]
Other investments, amortized cost	15,605	8,119
Other investments, carrying value	51,593	8,875
Other investments, unrealized gain (loss)	35,988	756
Other investments, at fair value	51,593	$ 8,875
Residential Transition Loans [Member]
Other investments, amortized cost	2,243
Other investments, carrying value	2,300
Other investments, unrealized gain (loss)	57
Other investments, at fair value	$ 2,300