Fair Value of Financial Instruments - Schedule of Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	$ 432,584	$ 324,310
Fixed Maturity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	401,529	293,085
Fixed Maturity [Member] | U.S. Government and Agency Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	23,455	7,008
Fixed Maturity [Member] | States, Municipalities and Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	63,020	42,120
Fixed Maturity [Member] | Special Revenue [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	188,940	134,381
Fixed Maturity [Member] | Industrial And Commercial Bank Of China Financial Services Llc [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	122,906	106,005
Fixed Maturity [Member] | Redeemable Preferred Stocks [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	3,208	3,571
Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	31,055	31,225
Equity Securities [Member] | Nonredeemable Preferred Stocks [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	12,327	11,678
Equity Securities [Member] | Equity Investment [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	18,728	19,547
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	34,485	38,007
Level 1 [Member] | Fixed Maturity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	3,430	6,782
Level 1 [Member] | Fixed Maturity [Member] | U.S. Government and Agency Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	222	3,211
Level 1 [Member] | Fixed Maturity [Member] | Redeemable Preferred Stocks [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	3,208	3,571
Level 1 [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	31,055	31,225
Level 1 [Member] | Equity Securities [Member] | Nonredeemable Preferred Stocks [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	12,327	11,678
Level 1 [Member] | Equity Securities [Member] | Equity Investment [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	18,728	19,547
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	398,099	286,303
Level 2 [Member] | Fixed Maturity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	398,099	286,303
Level 2 [Member] | Fixed Maturity [Member] | U.S. Government and Agency Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	23,233	3,797
Level 2 [Member] | Fixed Maturity [Member] | States, Municipalities and Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	63,020	42,120
Level 2 [Member] | Fixed Maturity [Member] | Special Revenue [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	188,940	134,381
Level 2 [Member] | Fixed Maturity [Member] | Industrial And Commercial Bank Of China Financial Services Llc [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total investments	$ 122,906	$ 106,005