Condensed Financial Information of HCI Group, Inc. - Statements of Cash Flows (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net (loss) income after noncontrolling interests	$ (58,511)	$ 1,856	$ 27,580
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Stock-based compensation expense	15,107	13,754	8,133
Net realized investment losses (gains)	1,187	(6,472)	(1,000)
Net unrealized investment losses (gains)	7,153	(1,363)	(679)
Net amortization of premiums (accretion of discount) on investments in fixed-maturity securities	(961)	169	(100)
Depreciation and amortization	8,010	5,549	8,747
Net (income) loss from limited partnership interests	(3,963)	(4,947)	1,595
Distributions from limited partnership interests	3,001	3,604	1,215
Credit losses on investments	0	0	(611)
Debt conversion expense	0	1,754	0
Loss on repurchases of convertible senior notes	0	0	150
Equity in loss (income) of subsidiaries	(495)	(417)	57
Total deferred taxes	(9,881)	1,142	8,123
Changes in operating assets and liabilities:
Income taxes	1,277	470	(3,514)
Other assets	(15,581)	4,487	(4,578)
Accrued expenses and other liabilities	(8,397)	1,642	20,303
Net cash (used in) provided by operating activities	(12)	96,503	77,311
Cash flows from investing activities:
Investments in limited partnership interests	(1,967)	(3,756)	(4,241)
Purchase of fixed-maturity securities	(614,843)	(18,303)	(34,951)
Purchase of equity securities	(22,887)	(102,801)	(68,223)
Purchase of short-term and other investments	(42)	(1,307)	(200)
Purchase of intangible assets	(3,800)	0	0
Purchase of property and equipment	(6,341)	(3,318)	(6,437)
Proceeds from sales of fixed-maturity securities	11,716	23,055	81,433
Proceeds from calls, repayments and maturities of fixed-maturity securities	151,415	23,430	84,459
Proceeds from sales of equity securities	31,605	112,310	47,312
Proceeds from sales, redemptions and maturities of short-term and other investments	570	3,629	997
Distributions received from limited partnership interests	5,360	4,657	2,086
Received distribution	351	623	0
Net cash (used in) provided by investing activities	(434,537)	36,852	143,215
Cash flows from financing activities:
Repurchases of common stock	(71,242)	(1,314)	(1,547)
Repurchases of common stock under share repurchase plan	(17,070)	0	(5,161)
Repurchases of convertible senior notes	0	0	(4,459)
Debt issuance costs	(6,041)	(152)	(165)
Cash dividends paid	(15,233)	(14,065)	(12,694)
Cash dividends received under share repurchase forward contract	76	306	306
Net (repayment) borrowing under revolving credit facility	(15,000)	(8,750)	14,000
Proceeds from exercise of stock options	0	0	63
Debt conversion expense paid	0	(1,895)	0
Net cash provided by (used in) financing activities	41,067	64,301	(16,705)
Net (decrease) increase in cash, cash equivalents, and restricted cash	(393,580)	197,602	203,823
Cash and cash equivalents at beginning of year	631,343
Cash and cash equivalents at end of year	237,763	631,343
HCI Group [Member]
Cash flows from operating activities:
Net (loss) income after noncontrolling interests	(58,511)	1,856	27,580
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Stock-based compensation expense	6,430	5,874	4,488
Net realized investment losses (gains)	1,154	(3,344)	(330)
Net unrealized investment losses (gains)	1,609	(92)	(229)
Net amortization of premiums (accretion of discount) on investments in fixed-maturity securities	(110)	3	(42)
Depreciation and amortization	1,403	1,490	4,686
Net (income) loss from limited partnership interests	(3,345)	(2,608)	1,781
Distributions from limited partnership interests	2,123	1,477	844
Credit losses on investments	0	0	20
Debt conversion expense	0	1,754	0
Loss on repurchases of convertible senior notes	0	0	150
Equity in loss (income) of subsidiaries	47,331	(9,274)	(41,440)
Total deferred taxes	(895)	232	(935)
Changes in operating assets and liabilities:
Income taxes	11,708	5,067	(9,791)
Other assets	(2,805)	2,679	(629)
Accrued expenses and other liabilities	4,078	(5,620)	1,096
Due to related parties	38,696	5,360	17,438
Net cash (used in) provided by operating activities	48,866	4,854	4,687
Cash flows from investing activities:
Investments in limited partnership interests	(1,261)	(2,616)	(3,376)
Investment in note receivable - related party	(15,000)	(40,000)	(22,000)
Purchase of fixed-maturity securities	(52,576)	(1,685)	(7)
Purchase of equity securities	(11,406)	(76,786)	(35,855)
Purchase of short-term and other investments	(42)	(1,307)	(200)
Purchase of intangible assets	(3,800)	0	0
Purchase of property and equipment	(581)	(365)	(742)
Proceeds from sales of fixed-maturity securities	86	134	447
Proceeds from calls, repayments and maturities of fixed-maturity securities	54,178	145	27
Proceeds from sales of equity securities	10,975	78,555	30,688
Proceeds from sales, redemptions and maturities of short-term and other investments	570	3,618	537
Collection of note receivable - related party	0	23,280	0
Distributions received from limited partnership interests	4,759	2,567	1,614
Dividends received from subsidiary	51,500	41,900	52,500
Received distribution	0	0	9
Investment in subsidiaries	(41,868)	(10,000)	(22,629)
Net cash (used in) provided by investing activities	(4,466)	17,440	1,013
Cash flows from financing activities:
Repurchases of common stock	(71,242)	(1,314)	(1,547)
Repurchases of common stock under share repurchase plan	(17,070)	0	(5,161)
Repurchases of convertible senior notes	0	0	(4,459)
Debt issuance costs	(6,041)	(152)	0
Cash dividends paid	(15,233)	(14,065)	(12,694)
Cash dividends received under share repurchase forward contract	76	306	306
Net (repayment) borrowing under revolving credit facility	(15,000)	(8,750)	14,000
Proceeds from exercise of stock options	0	0	63
Debt conversion expense paid	0	(1,895)	0
Proceeds from issuance of long-term debt	172,500	0	0
Repayment of long-term debt	(1)	(2)	(2)
Net cash provided by (used in) financing activities	47,989	(25,872)	(9,494)
Net (decrease) increase in cash, cash equivalents, and restricted cash	92,389	(3,578)	(3,794)
Cash and cash equivalents at beginning of year	10,366	13,944	17,738
Cash and cash equivalents at end of year	$ 102,755	$ 10,366	$ 13,944