Investments - Amortized Cost and Fair Value of Fixed Maturity Securities by Contractual Maturity (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Amortized Cost
Due in one year or less	$ 8,134	$ 5,628
Due after one year through five years	10,227	13,863
Due after five years through ten years	330	330
Amortized Cost, Total	18,691	19,821
Fair Value
Due in one year or less	8,137	5,628
Due after one year through five years	10,304	13,897
Due after five years through ten years	345	337
Fair Value, Total	$ 18,786	$ 19,862