Fair Value - Presentation of Fair-Value Measurements for Each Major Category of Assets Measured on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	$ 121,513	$ 130,248
Other investments	9,922	7,513
Fair Value Measurements Using [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	121,513	130,248
Other investments	9,922	7,513
Cash and cash equivalents	96,496	72,033
Total	227,931	209,794
Fair Value Measurements Using [Member] | Preferred Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	1,721	1,578
Fair Value Measurements Using [Member] | Equity Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual funds, available-for-sale	10,771	10,737
Fixed Maturities | Fair Value Measurements Using [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	109,021	117,933
Fixed Maturities | Fair Value Measurements Using [Member] | US Government Agencies Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	4,287	12,485
Fixed Maturities | Fair Value Measurements Using [Member] | State Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	731	736
Fixed Maturities | Fair Value Measurements Using [Member] | Political Subdivisions Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	508	612
Fixed Maturities | Fair Value Measurements Using [Member] | Revenue And Assessment Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	12,519	14,658
Fixed Maturities | Fair Value Measurements Using [Member] | Corporate Bond Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	76,426	73,325
Fixed Maturities | Fair Value Measurements Using [Member] | Collateralized Agency Backed Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	7,071	7,514
Fixed Maturities | Fair Value Measurements Using [Member] | Collateralized Non Agency Backed Residential Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	4,358	4,660
Fixed Maturities | Fair Value Measurements Using [Member] | Collateralized Non Agency Backed Commercial Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	3,121	3,943
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurements Using [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	16,779	24,800
Cash and cash equivalents	96,496	72,033
Total	113,275	96,833
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurements Using [Member] | Preferred Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	1,721	1,578
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurements Using [Member] | Equity Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual funds, available-for-sale	10,771	10,737
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Maturities | Fair Value Measurements Using [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	4,287	12,485
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fixed Maturities | Fair Value Measurements Using [Member] | US Government Agencies Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	4,287	12,485
Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurements Using [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	104,734	105,448
Total	104,734	105,448
Significant Other Observable Inputs (Level 2) [Member] | Fixed Maturities | Fair Value Measurements Using [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	104,734	105,448
Significant Other Observable Inputs (Level 2) [Member] | Fixed Maturities | Fair Value Measurements Using [Member] | State Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	731	736
Significant Other Observable Inputs (Level 2) [Member] | Fixed Maturities | Fair Value Measurements Using [Member] | Political Subdivisions Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	508	612
Significant Other Observable Inputs (Level 2) [Member] | Fixed Maturities | Fair Value Measurements Using [Member] | Revenue And Assessment Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	12,519	14,658
Significant Other Observable Inputs (Level 2) [Member] | Fixed Maturities | Fair Value Measurements Using [Member] | Corporate Bond Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	76,426	73,325
Significant Other Observable Inputs (Level 2) [Member] | Fixed Maturities | Fair Value Measurements Using [Member] | Collateralized Agency Backed Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	7,071	7,514
Significant Other Observable Inputs (Level 2) [Member] | Fixed Maturities | Fair Value Measurements Using [Member] | Collateralized Non Agency Backed Residential Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	4,358	4,660
Significant Other Observable Inputs (Level 2) [Member] | Fixed Maturities | Fair Value Measurements Using [Member] | Collateralized Non Agency Backed Commercial Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, available-for-sale	3,121	3,943
Significant Unobservable Inputs (Level 3) [Member] | Fair Value Measurements Using [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other investments	9,922	7,513
Total	$ 9,922	$ 7,513