Fair Value - Presentation of Fair-Value Measurements for Each Major Category of Assets Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	$ 117,212	$ 131,582
Other investments	9,994	11,256
Cash, cash equivalents, and restricted cash	118,681	115,587	$ 102,429	$ 72,033
Cash and cash equivalents		115,587
Total	245,887	258,425
Other investments	5,136	7,980
Total	5,136	7,980
Fixed Maturities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	101,589	118,442
Fixed Maturities | U.S. government and agencies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	18,951	13,113
Fixed Maturities | State
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale		702
Fixed Maturities | Political subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	4,165	4,363
Fixed Maturities | Revenue and assessment
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	5,683	12,644
Fixed Maturities | Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	45,540	80,785
Fixed Maturities | Collateralized mortgage obligations: Agency Backed
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	22,422	873
Fixed Maturities | Collateralized mortgage obligations: Non-agency backed - residential
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	2,933	3,455
Fixed Maturities | Collateralized mortgage obligations: Non-agency backed - commercial
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	1,895	2,507
Preferred stock, available-for-sale
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	3,112	1,723
Mutual funds, available-for-sale
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	12,511	11,417
Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	34,574	26,253
Cash, cash equivalents, and restricted cash	118,681
Cash and cash equivalents		115,587
Total	153,255	141,840
Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed Maturities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	18,951	13,113
Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets (Level 1) | Fixed Maturities | U.S. government and agencies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	18,951	13,113
Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets (Level 1) | Preferred stock, available-for-sale
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	3,112	1,723
Fair Value Measurements Using Quoted Prices in Active Markets for Identical Assets (Level 1) | Mutual funds, available-for-sale
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	12,511	11,417
Fair Value Measurements Using Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	82,638	105,329
Total	82,638	105,329
Fair Value Measurements Using Significant Other Observable Inputs (Level 2) | Fixed Maturities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	82,638	105,329
Fair Value Measurements Using Significant Other Observable Inputs (Level 2) | Fixed Maturities | State
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale		702
Fair Value Measurements Using Significant Other Observable Inputs (Level 2) | Fixed Maturities | Political subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	4,165	4,363
Fair Value Measurements Using Significant Other Observable Inputs (Level 2) | Fixed Maturities | Revenue and assessment
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	5,683	12,644
Fair Value Measurements Using Significant Other Observable Inputs (Level 2) | Fixed Maturities | Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	45,540	80,785
Fair Value Measurements Using Significant Other Observable Inputs (Level 2) | Fixed Maturities | Collateralized mortgage obligations: Agency Backed
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	22,422	873
Fair Value Measurements Using Significant Other Observable Inputs (Level 2) | Fixed Maturities | Collateralized mortgage obligations: Non-agency backed - residential
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	2,933	3,455
Fair Value Measurements Using Significant Other Observable Inputs (Level 2) | Fixed Maturities | Collateralized mortgage obligations: Non-agency backed - commercial
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, available-for-sale	1,895	2,507
Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other investments	4,858	3,276
Total	$ 4,858	$ 3,276