Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 03, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Trading Symbol	HCI
Entity Registrant Name	HCI Group, Inc.
Entity Central Index Key	0001400810
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common Shares
Security Exchange Name	NYSE
Entity File Number	001-34126
Entity Incorporation, State or Country Code	FL
Entity Tax Identification Number	20-5961396
Entity Address, Address Line One	3802 Coconut Palm Drive
Entity Address, City or Town	Tampa
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33619
City Area Code	813
Local Phone Number	849-9500
Document Quarterly Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		10,250,656