Investment Securities - Schedule of Investments in Accordance with Fair Value Measurement (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	$ 99,055	$ 60,641
Total investments fair value	106,356	149,492
Money Market Funds [Member]
Class of securities:
Money market funds	7,301	88,851
Level 1
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	75,037	20,770
Total investments fair value	82,338	109,621
Level 1 | Money Market Funds [Member]
Class of securities:
Money market funds	7,301	88,851
Level 2
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	24,018	39,871
Total investments fair value	24,018	39,871
U.S. Government Treasury Securities [Member]
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	248
U.S. Government Treasury Securities [Member] | Level 1
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	248
Obligations of U.S. Government Sponsored Enterprises [Member]
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	69,382	6,475
Obligations of U.S. Government Sponsored Enterprises [Member] | Level 1
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	63,909	3,009
Obligations of U.S. Government Sponsored Enterprises [Member] | Level 2
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	5,473	3,466
Corporate Debt Securities [Member]
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	21,061	41,484
Corporate Debt Securities [Member] | Level 1
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	8,873	14,939
Corporate Debt Securities [Member] | Level 2
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	12,188	26,545
Foreign Corporate Debt Securities [Member]
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	8,364	12,682
Foreign Corporate Debt Securities [Member] | Level 1
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	2,007	2,822
Foreign Corporate Debt Securities [Member] | Level 2
Class of securities:
Total fixed-maturity securities, Estimated Fair Value	$ 6,357	$ 9,860