Regulatory Requirements and Restrictions - Summary of Required Ratio of Gross and Net Written Premium to Surplus (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
HCPCI [Member]
Statutory Accounting Practices [Line Items]
Premium to capital surplus ratio for gross written premiums	2.01	1.81	1.85
Premium to capital surplus ratio for net written premiums	1.11	1.07	1.00
TypTap [Member]
Statutory Accounting Practices [Line Items]
Premium to capital surplus ratio for gross written premiums	0.33	0.09
Premium to capital surplus ratio for net written premiums	0.27	0.07