Note 4 - Insurance SPAC Investments and Other Significant Events - Income Statement Impact (Details) - USD ($) $ in Thousands	1 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Principal transactions and other income									$ 45,506	$ 2,103	$ 4,573
Equity-based compensation									(12,553)	(744)	(623)
Other operating									(19,997)	(19,653)	(20,342)
Loss from equity method affiliates	$ (244)	$ (1,371)	$ (1,233)	$ (107)	$ (188)	$ (109)	$ (248)	$ (8)	(2,955)	(553)
Net income / (loss)	43,626	3,343	3,269	(11,785)	1,197	(1,918)	(1,028)	(1,824)	38,453	(3,573)	(3,987)
Less: Net income / (loss) attributable to the non-controlling interest									24,248	(1,519)	(1,524)
Net Income (Loss) Attributable to Parent	14,751	$ 1,655	$ 901	$ (3,102)	$ 774	$ (1,216)	$ (410)	$ (1,202)	14,205	$ (2,054)	$ (2,463)
Insurance SPAC [Member]
Principal transactions and other income									41,035
Equity-based compensation									(11,700)
Other operating									(2)
Loss from equity method affiliates									(3,138)
Net income / (loss)									26,195
Less: Net income / (loss) attributable to the non-controlling interest									(9,328)
Net income / (loss) - Operating LLC									16,867
Less: Net income / (loss) attributable to the convertible non-controlling interest	12,205								12,205
Net Income (Loss) Attributable to Parent									4,662
Insurance SPAC Pipe Sponsor LLC [Member]
Principal transactions and other income									(842)
Equity-based compensation
Other operating
Loss from equity method affiliates
Net income / (loss)									(842)
Less: Net income / (loss) attributable to the non-controlling interest									410
Net income / (loss) - Operating LLC									(432)
Less: Net income / (loss) attributable to the convertible non-controlling interest	(313)								(313)
Net Income (Loss) Attributable to Parent									(119)
Operating LLC [Member]
Principal transactions and other income									426
Equity-based compensation
Other operating
Loss from equity method affiliates
Net income / (loss)									426
Less: Net income / (loss) attributable to the non-controlling interest
Net income / (loss) - Operating LLC									426
Less: Net income / (loss) attributable to the convertible non-controlling interest	308								308
Net Income (Loss) Attributable to Parent									118
All Insurance SPACs [Member]
Principal transactions and other income									40,619
Equity-based compensation									(11,700)
Other operating									(2)
Loss from equity method affiliates									(3,138)
Net income / (loss)									25,779
Less: Net income / (loss) attributable to the non-controlling interest									(8,918)
Net income / (loss) - Operating LLC									16,861
Less: Net income / (loss) attributable to the convertible non-controlling interest	$ 12,200								12,200
Net Income (Loss) Attributable to Parent									$ 4,661