Schedule VI. Supplemental Information Concerning Property-Casualty Insurance Operations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplemental Information for Property, Casualty Insurance Underwriters [Abstract]
Deferred Policy Acquisition Cost	$ 19,649	$ 19,171	$ 18,419
Reserves for Unpaid Loss and Loss Adjustment Expense	687,602	614,557	570,450
Unearned Premium	168,576	164,296	140,528
Earned Premium	375,747	329,983	290,689
Net Investment Income	27,214	27,029	27,018
Loss and LAE Related to Current Period	268,633	241,584	222,393
Loss and LAE Related to Prior Periods	(23,717)	(12,611)	(2,490)
Amortization of Deferred Policy Acquisition Costs	(43,817)	(40,526)	(39,120)
Paid Claims and Claim Adjustment Expenses	182,506	178,375	181,920
Net Premiums Written	$ 380,026	$ 353,752	$ 312,518

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Amount of amortization expense on deferred policy acquisition cost.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 235

-Section S99

-Paragraph 3

-Subparagraph (SX 210.12-18)

-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e575016-122915

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 18

-Article 12

+ Details

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Amount of expense for claims incurred in the current reporting period and related claims settlement costs.

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Amount of deferred policy acquisition cost related to property-casualty insurance policy written.

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- Definition

Amount of property-casualty insurance premium revenue earned on insurance policies.

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Amount of net investment income earned by property-casualty insurance underwriter.

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Payments of claims and claims adjustment expenses during the period of a property-casualty insurance entity.

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Amount of actual premium written by property-casualty insurance underwriter.

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Amount of expense for claims incurred in prior reporting periods and related claims settlement costs.

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The amount of reserve, policy claim payable and loss expense incurred by property-casualty insurance underwriter.

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Amount of property-casualty insurance premium revenue not yet earned on insurance policies.

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