Fair Value of Financial Instruments - Summary of Securities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equities		$ 6,004	$ 6,209
Separate accounts		20,819	24,779	$ 21,513
Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		184,475	188,452
Equities		6,004	6,209
Derivative instruments		202	395
Cash equivalents	[1]	33,252	4,085
Separate accounts	[2]	20,819	24,779
Total		244,752	223,920
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		4,057	4,162
Equities		3,733	4,027
Derivative instruments		202	395
Cash equivalents	[1]	33,252	4,085
Separate accounts	[2]	20,819	24,779
Total		62,063	37,448
Significant Other Observable Inputs (Level 2) | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		180,418	184,290
Total		180,418	184,290
Significant Other Unobservable Inputs (Level 3) | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equities		2,271	2,182
Total		2,271	2,182
U.S. government | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		4,057	4,162
U.S. government | Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		4,057	4,162
States, Political Subdivisions, Other | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		30,989	27,614
States, Political Subdivisions, Other | Significant Other Observable Inputs (Level 2) | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		30,989	27,614
Corporate | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		106,286	109,395
Corporate | Significant Other Observable Inputs (Level 2) | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		106,286	109,395
Residential Mortgage-Backed Securities | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		37,522	43,086
Residential Mortgage-Backed Securities | Significant Other Observable Inputs (Level 2) | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		37,522	43,086
Commercial Mortgage-Backed Securities | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		5,621	4,195
Commercial Mortgage-Backed Securities | Significant Other Observable Inputs (Level 2) | Recurring Fair Value Measurements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total Fixed maturities		$ 5,621	$ 4,195

[1] Cash equivalents are invested in money market funds with daily liquidity. The estimated fair value of cash equivalents is based on the estimated fair value of the underlying assets as provided by fund managers in daily net asset values and included in Level 1 assets.

[2] Separate account assets are invested in money market funds with daily liquidity. The estimated fair value of separate account assets is based on the estimated fair value of the underlying assets as provided by fund managers in daily net asset values and included in Level 1 assets.