Statutory Financial Information - Additional Information (Detail) - Wright Flood - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Statutory Accounting Practices [Line Items]
Statutory capital and surplus required	$ 7,500,000
Statutory capital and surplus	25,300,000	$ 23,500,000
Statutory net Income	$ 1,600,000	$ 8,200,000