Investments - Summary of Company's Investment Securities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investment Securities [Line Items]
Amortized Cost	$ 129,742	$ 117,902
Gross Unrealized Gains	2,646	2,389
Gross Unrealized Losses	(2,443)	(3,079)
Fair Value	129,945	117,212
Fixed Maturities
Investment Securities [Line Items]
Amortized Cost	114,904	103,064
Gross Unrealized Gains	1,327	1,493
Gross Unrealized Losses	(2,329)	(2,968)
Fair Value	113,902	101,589
Fixed Maturities \| U.S. government and agencies
Investment Securities [Line Items]
Amortized Cost	19,642	19,142
Gross Unrealized Gains	70	112
Gross Unrealized Losses	(365)	(303)
Fair Value	19,347	18,951
Fixed Maturities \| Political subdivisions
Investment Securities [Line Items]
Amortized Cost	4,111	4,233
Gross Unrealized Losses	(28)	(68)
Fair Value	4,083	4,165
Fixed Maturities \| Revenue and assessment
Investment Securities [Line Items]
Amortized Cost	5,145	5,539
Gross Unrealized Gains	178	185
Gross Unrealized Losses	(5)	(41)
Fair Value	5,318	5,683
Fixed Maturities \| Corporate bonds
Investment Securities [Line Items]
Amortized Cost	44,070	47,238
Gross Unrealized Gains	50	107
Gross Unrealized Losses	(1,145)	(1,805)
Fair Value	42,975	45,540
Fixed Maturities \| Collateralized mortgage obligations: Agency Backed
Investment Securities [Line Items]
Amortized Cost	39,823	23,093
Gross Unrealized Gains	61	73
Gross Unrealized Losses	(780)	(744)
Fair Value	39,104	22,422
Fixed Maturities \| Collateralized mortgage obligations: Non-agency backed - residential
Investment Securities [Line Items]
Amortized Cost	2,059	2,411
Gross Unrealized Gains	617	529
Gross Unrealized Losses	(6)	(7)
Fair Value	2,670	2,933
Fixed Maturities \| Collateralized mortgage obligations: Non-agency backed - commercial
Investment Securities [Line Items]
Amortized Cost	54	1,408
Gross Unrealized Gains	351	487
Fair Value	405	1,895
Preferred stock, available-for-sale
Investment Securities [Line Items]
Amortized Cost	3,025	3,025
Gross Unrealized Gains	193	198
Gross Unrealized Losses	(114)	(111)
Fair Value	3,104	3,112
Mutual funds, available-for-sale
Investment Securities [Line Items]
Amortized Cost	11,813	11,813
Gross Unrealized Gains	1,126	698
Fair Value	$ 12,939	$ 12,511

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- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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