Condensed Financial Information of HCI Group, Inc. - Statements of Income (Detail) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Condensed Financial Statements Captions [Line Items]
Net investment income													$ 46,234	$ 32,447	$ 12,335
Net realized investment (losses) gains													(1,996)	(1,187)	6,472
Net unrealized investment gains (losses)													3,215	(7,153)	1,363
Credit loss expense													0	0	0
Other income													2,628	4,488	6,447
Interest expense	$ (2,822)	$ (2,827)	$ (2,667)	$ (2,801)	$ (2,839)	$ (2,813)	$ (1,515)	$ (601)	$ (657)	$ (1,664)	$ (2,000)	$ (2,079)	(11,117)	(7,768)	(6,400)
Debt conversion expense													0	0	(1,754)
Income tax benefit													(28,393)	13,815	(3,991)
Equity in income (loss) of subsidiaries													0	495	417
Net income (loss)													79,034	(58,511)	1,856
HCI Group [Member]
Condensed Financial Statements Captions [Line Items]
Net investment income													7,607	5,498	3,115
Net realized investment (losses) gains													(554)	(1,154)	3,344
Net unrealized investment gains (losses)													1,060	(1,609)	92
Other income													2	1,138	222
Interest expense													(10,397)	(6,876)	(5,467)
Debt conversion expense													0	0	(1,754)
Operating expenses													(6,398)	(9,877)	(9,056)
Loss before income tax benefit and equity in income (loss) of subsidiaries													(8,680)	(12,880)	(9,504)
Income tax benefit													2,336	1,700	2,086
Net loss before equity in income (loss) of subsidiaries													(6,344)	(11,180)	(7,418)
Equity in income (loss) of subsidiaries													70,832	(47,331)	9,274
Net income (loss)													$ 64,488	$ (58,511)	$ 1,856