Losses and Loss Adjustment Reserve - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2016 USD ($) Reinsurer	Dec. 31, 2015 USD ($)
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Ceded rate of premiums under insurance program	100.00%
Premiums written net	$ 286,416,000
Ceded unpaid loss	60,800,000
Prepaid reinsurance premiums	298,907,000	$ 309,643,000
Increase (Decrease) in Loss and Loss Adjustment Expense Reserve	0
Reserve for losses and loss adjustment expense	$ 60,800,000
Number of reinsurers | Reinsurer	2
Homeowners
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Ceded unpaid loss	$ 8,698
Reinsurance recoverable, incurred but not reported claims	10,335
Private Passenger Auto Liability
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Ceded unpaid loss	8,400
Reinsurance recoverable, incurred but not reported claims	14,383
Other Liability
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Ceded unpaid loss	$ 0
Wright Flood
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Ceded rate of premiums under insurance program	100.00%
Expenses and allowance rate received in premiums	30.90%
Premiums written net	$ 285,700,000
Wright Flood | Quota Share Agreement
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Effective cedes rate under quota share agreement	100.00%
Commission rate, percent of ceded written premiums	30.50%
Ceded amount	$ 700,000