Note 7 - Underwriting Information - Schedule of Gross Written Premiums (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 496,288	$ 385,184	$ 938,452	$ 753,262
Percentage of Gross Written Premiums	100.00%	100.00%	100.00%	100.00%
Palomar Specialty Insurance Company [Member]
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 232,983	$ 193,709	$ 463,900	$ 416,366
Percentage of Gross Written Premiums	46.90%	50.30%	49.40%	55.30%
Palomar Excess And Surplus Insurance Company [Member]
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 237,943	$ 177,109	$ 428,730	$ 313,603
Percentage of Gross Written Premiums	47.90%	46.00%	45.70%	41.60%
Laulima Insurance Company [Member]
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 20,134	$ 14,366	$ 36,171	$ 23,293
Percentage of Gross Written Premiums	4.10%	3.70%	3.90%	3.10%
First Indemnity of America Insurance Company [Member]
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 5,228	$ 0	$ 9,651	$ 0
Percentage of Gross Written Premiums	1.10%	0.00%	1.00%	0.00%
CALIFORNIA
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 163,814	$ 183,396	$ 303,536	$ 340,614
Percentage of Gross Written Premiums	33.00%	47.60%	32.30%	45.20%
TEXAS
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 35,708	$ 28,600	$ 80,699	$ 69,396
Percentage of Gross Written Premiums	7.20%	7.40%	8.60%	9.20%
HAWAII
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 24,544	$ 18,235	$ 44,901	$ 30,751
Percentage of Gross Written Premiums	4.90%	4.70%	4.80%	4.10%
FLORIDA
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 23,979	$ 29,796	$ 42,621	$ 43,720
Percentage of Gross Written Premiums	4.80%	7.70%	4.50%	5.80%
NEW YORK
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 17,462	$ 7,980	$ 32,857	$ 16,010
Percentage of Gross Written Premiums	3.50%	2.10%	3.50%	2.10%
WASHINGTON
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 17,188	$ 13,063	$ 32,059	$ 25,066
Percentage of Gross Written Premiums	3.50%	3.40%	3.40%	3.30%
ILLINOIS
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 13,048	$ 4,870	$ 18,637	$ 8,168
Percentage of Gross Written Premiums	2.70%	1.30%	2.00%	1.10%
MINNESOTA
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 12,004	$ 1,243	$ 13,042	$ 2,440
Percentage of Gross Written Premiums	2.40%	0.30%	1.40%	0.30%
Other States [Member]
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 188,541	$ 98,001	$ 370,100	$ 217,097
Percentage of Gross Written Premiums	38.00%	25.50%	39.50%	28.90%
Earthquake Premiums [Member]
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 147,702	$ 135,029	$ 277,929	$ 240,759
Percentage of Gross Written Premiums	29.80%	35.10%	29.70%	32.00%
Casualty [Member]
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 128,222	$ 58,605	$ 238,932	$ 110,539
Percentage of Gross Written Premiums	25.80%	15.20%	25.50%	14.70%
Inland Marine and Other Property [Member]
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 120,031	$ 93,453	$ 219,098	$ 170,329
Percentage of Gross Written Premiums	24.20%	24.30%	23.30%	22.60%
Fronting Premium [Member]
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 60,869	$ 95,896	$ 114,810	$ 190,727
Percentage of Gross Written Premiums	12.20%	24.90%	12.20%	25.30%
Crop [Member]
Disaggregation of Revenue [Line Items]
Gross written premiums	$ 39,464	$ 2,201	$ 87,683	$ 40,908
Percentage of Gross Written Premiums	8.00%	0.50%	9.30%	5.40%