Note 10 - Reinsurance (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2021 USD ($)
Reinsurance, Amount Retained, Per Event	$ 13,400	$ 10,700
Prepaid Reinsurance Premiums	265,808	204,084
Catastrophe Bond, Face Value				$ 200,000	$ 275,000	$ 400,000
Ceded Premiums Written	731,531	524,575	$ 223,443
Ceded Premiums Earned	669,808	378,806	200,172
Largest Reinsurer One [Member]
Ceded Premiums Earned	152,400	24,700	24,700
Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments	69,500	60,600
Largest Reinsurer Two [Member]
Ceded Premiums Earned	65,900	22,900	11,700
Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments	29,800	53,900
Largest Reinsurer Three [Member]
Ceded Premiums Earned	47,400	18,400	$ 10,400
Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments	$ 25,500	$ 50,600
Reinsurer Concentration Risk [Member] | Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments [Member]
Number of Largest Reinsurers	3	3	3
Reinsurer Concentration Risk [Member] | Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments [Member] | Three Largest Reinsurers [Member]
Concentration Risk, Percentage	36.30%	23.90%	20.90%
Reinsurer Concentration Risk [Member] | Reinsurance Recoverable Including Reinsurance Premium Paid [Member] | Three Largest Reinsurers [Member]
Number of Largest Reinsurers	3	3
Concentration Risk, Percentage	45.70%	31.50%
Catastrophe [Member]
Reinsurance, Amount Retained, Per Event	$ 17,500
Ceded Premiums Written	42,700	$ 28,300	$ 11,700
Earthquake [Member]
Reinsurance Policy, Excess of Loss Protection Amount	2,710
Hawaii Hurricane [Member]
Reinsurance Policy, Excess of Loss Protection Amount	900,000
U.S. Hurricane [Member]
Reinsurance Policy, Excess of Loss Protection Amount	$ 100,000