Note 7 - Underwriting Information - Schedule of Gross Written Premiums (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Gross written premiums	$ 313,998	$ 253,128	$ 838,406	$ 642,751
Percentage of Gross Written Premiums	100.00%	100.00%	100.00%	100.00%
Palomar Specialty Insurance Company [Member]
Gross written premiums	$ 186,693	$ 136,814	$ 497,216	$ 357,156
Percentage of Gross Written Premiums	59.50%	54.00%	59.30%	55.60%
Palomar Excess And Surplus Insurance Company [Member]
Gross written premiums	$ 127,305	$ 116,314	$ 341,190	$ 285,595
Percentage of Gross Written Premiums	40.50%	46.00%	40.70%	44.40%
CALIFORNIA
Gross written premiums	$ 163,806	$ 131,016	$ 450,752	$ 292,865
Percentage of Gross Written Premiums	52.20%	51.80%	53.80%	45.60%
TEXAS
Gross written premiums	$ 24,336	$ 26,234	$ 72,777	$ 71,499
Percentage of Gross Written Premiums	7.70%	10.40%	8.70%	11.10%
WASHINGTON
Gross written premiums	$ 17,792	$ 13,573	$ 43,409	$ 29,391
Percentage of Gross Written Premiums	5.70%	5.40%	5.20%	4.60%
HAWAII
Gross written premiums	$ 13,490	$ 10,998	$ 35,824	$ 29,729
Percentage of Gross Written Premiums	4.30%	4.30%	4.30%	4.60%
FLORIDA
Gross written premiums	$ 11,549	$ 7,445	$ 36,309	$ 27,216
Percentage of Gross Written Premiums	3.70%	2.90%	4.30%	4.20%
OREGON
Gross written premiums	$ 8,536	$ 7,738	$ 21,223	$ 16,483
Percentage of Gross Written Premiums	2.70%	3.10%	2.50%	2.60%
ILLINOIS
Gross written premiums	$ 6,502	$ 4,204	$ 15,675	$ 13,153
Percentage of Gross Written Premiums	2.10%	1.70%	1.90%	2.00%
TENNESSEE
Gross written premiums	$ 5,562	$ 1,810	$ 9,233	$ 4,247
Percentage of Gross Written Premiums	1.80%	0.70%	1.10%	0.70%
Other States [Member]
Gross written premiums	$ 62,425	$ 50,110	$ 153,204	$ 158,168
Percentage of Gross Written Premiums	19.80%	19.80%	18.20%	24.60%
Fronting Premium [Member]
Gross written premiums	$ 106,581	$ 82,232	$ 278,548	$ 154,232
Percentage of Gross Written Premiums	33.90%	32.50%	33.20%	24.00%
Residential Earthquake [Member]
Gross written premiums	$ 69,220	$ 59,569	$ 190,048	$ 159,995
Percentage of Gross Written Premiums	22.00%	23.50%	22.70%	24.90%
Commercial Earthquake [Member]
Gross written premiums	$ 44,166	$ 32,647	$ 124,763	$ 90,894
Percentage of Gross Written Premiums	14.10%	12.90%	14.90%	14.10%
Inland Marine [Member]
Gross written premiums	$ 37,252	$ 30,842	$ 103,841	$ 72,214
Percentage of Gross Written Premiums	11.90%	12.20%	12.40%	11.20%
Casualty [Member]
Gross written premiums	$ 20,165	$ 12,888	$ 50,144	$ 25,697
Percentage of Gross Written Premiums	6.40%	5.10%	6.00%	4.00%
Hawaii Hurricane [Member]
Gross written premiums	$ 11,051	$ 9,425	$ 28,718	$ 24,579
Percentage of Gross Written Premiums	3.50%	3.70%	3.40%	3.80%
Commercial All Risk [Member]
Gross written premiums	$ 6,624	$ 9,224	$ 26,769	$ 41,647
Percentage of Gross Written Premiums	2.10%	3.60%	3.20%	6.50%
Flood Insurance Product [Member]
Gross written premiums	$ 5,259	$ 3,871	$ 14,964	$ 10,448
Percentage of Gross Written Premiums	1.70%	1.50%	1.80%	1.60%
Specialty Homeowners [Member]
Gross written premiums		$ (94)	$ (99)	$ 30,082
Percentage of Gross Written Premiums	(0.00%)	(0.00%)	(0.00%)	4.70%
Specialty Homeowners	$ (2)
Service, Other [Member]
Gross written premiums	$ 13,682	$ 12,524	$ 20,710	$ 32,963
Percentage of Gross Written Premiums	4.40%	5.00%	2.40%	5.20%