Investment Securities - Schedule of Investments in Accordance with Fair Value Measurement (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	$ 98,126	$ 99,055
Total investments fair value	101,412	106,356
Money Market Funds [Member]
Class of securities:
Money market funds	3,286	7,301
Level 1
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	78,741	75,037
Total investments fair value	82,027	82,338
Level 1 | Money Market Funds [Member]
Class of securities:
Money market funds	3,286	7,301
Level 2
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	19,385	24,018
Total investments fair value	19,385	24,018
U.S. Government Treasury Securities [Member]
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	250	248
U.S. Government Treasury Securities [Member] | Level 1
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	250	248
Obligations of U.S. Government Sponsored Enterprises [Member]
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	68,473	69,382
Obligations of U.S. Government Sponsored Enterprises [Member] | Level 1
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	63,974	63,909
Obligations of U.S. Government Sponsored Enterprises [Member] | Level 2
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	4,499	5,473
Corporate Debt Securities [Member]
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	21,029	21,061
Corporate Debt Securities [Member] | Level 1
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	12,007	8,873
Corporate Debt Securities [Member] | Level 2
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	9,022	12,188
Foreign Corporate Debt Securities [Member]
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	8,374	8,364
Foreign Corporate Debt Securities [Member] | Level 1
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	2,510	2,007
Foreign Corporate Debt Securities [Member] | Level 2
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	$ 5,864	$ 6,357