Investments - Summary of Proceeds Received and Gross Realized Gains and Losses from Sales of Available for Sale Securities (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fixed-Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Proceeds	$ 47,557	$ 390	$ 67,519	$ 1,749
Gross Realized Gains	2,759	58	3,623	92
Gross Realized Losses		(1)	(9)	(4)
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Proceeds	3,302	708	9,232	2,021
Gross Realized Gains	623	20	1,131	84
Gross Realized Losses	$ (88)	$ (46)	$ (280)	$ (129)