Losses and Loss Adjustment Reserve - Additional Information (Detail) $ in Thousands	3 Months Ended
Mar. 31, 2019 USD ($) Reinsurer	Dec. 31, 2018 USD ($)
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Ceded rate of premiums under insurance program	100.00%
Document Period End Date	Mar. 31, 2019
Premiums written net	$ 133,317
Ceded unpaid loss	51,400
Prepaid reinsurance premiums	314,363	$ 337,920
Reserve for losses and loss adjustment expense	$ 51,400
Number of reinsurers \| Reinsurer	2
Wright National Flood Insurance Company [Member]
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	30.00%
Premiums written net	$ 132,900
Wright National Flood Insurance Company [Member] \| 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	$ 400

Number of reinsurers.

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Percentage of ceded premiums.

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Percentage of flood premiums ceded.

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- Definition

Percentage of reinsurance recoverables allowance.

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Reinsurance percentage of ceding commission.

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- Definition

Reserve For Losses And Loss Adjustment Expenses For Reinsurance Liability

+ References

No definition available.

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The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements containing historical data, it is the date up through which that historical data is presented. If there is no historical data in the report, use the filing date. The format of the date is CCYY-MM-DD.

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Amount of written premiums ceded to other entities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 605
-Section 50
-Paragraph 1
-Subparagraph (c)(2)
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The unexpired portion of premiums ceded on policies in force as of the balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after valuation allowance, recoverable under reinsurance contracts for losses reported to the ceding insurer but not yet paid and amounts expected for incurred losses and settlement expenses, which have not yet been reported to the ceding insurer.

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Amount, after valuation allowance, recoverable under reinsurance contracts including premium paid under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

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