Fair Value - Presentation of Fair-Value Measurements for Each Major Category of Assets Measured on Recurring Basis (Detail) - USD ($) $ in Thousands | Mar. 31, 2016 | Dec. 31, 2015 |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | | |
Investments, available-for-sale | $ 130,898 | $ 131,582 |
Other investments | 10,286 | 11,256 |
Cash and cash equivalents | 128,906 | 115,587 |
Total | 270,090 | 258,425 |
Fixed Maturities | | |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | | |
Investments, available-for-sale | 117,541 | 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 | 13,366 | 13,113 |
Fixed Maturities | State | | |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | | |
Investments, available-for-sale | 703 | 702 |
Fixed Maturities | Political subdivisions | | |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | | |
Investments, available-for-sale | 4,374 | 4,363 |
Fixed Maturities | Revenue and assessment | | |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | | |
Investments, available-for-sale | 11,278 | 12,644 |
Fixed Maturities | Corporate bonds | | |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | | |
Investments, available-for-sale | 81,598 | 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 | 867 | 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 | 3,230 | 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 | 2,125 | 2,507 |
Preferred stock, available-for-sale | | |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | | |
Investments, available-for-sale | 1,765 | 1,723 |
Mutual funds, available-for-sale | | |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | | |
Investments, available-for-sale | 11,592 | 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 | 26,723 | 26,253 |
Cash and cash equivalents | 128,906 | 115,587 |
Total | 155,629 | 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 | 13,366 | 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 | 13,366 | 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 | 1,765 | 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 | 11,592 | 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 | 104,175 | 105,329 |
Total | 104,175 | 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 | 104,175 | 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 | 703 | 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 | 4,374 | 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 | 11,278 | 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 | 81,598 | 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 | 867 | 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 | 3,230 | 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 | 2,125 | 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 | 3,483 | 3,276 |
Total | 3,483 | 3,276 |
Fair Value Measurements Using Proportionate Share of Net Assets (NAV) | | |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | | |
Other investments | 6,803 | 7,980 |
Total | $ 6,803 | $ 7,980 |