Losses and Loss Adjustment Expenses - Liability for Losses and Loss Adjustment Expenses (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Liability For Unpaid Claims And Claims Adjustment Expense Net [Abstract]
Balance, beginning of period	$ 43,686	$ 41,168
Incurred related to:
Current period	18,914	16,931
Prior period	(349)	(1,059)
Total incurred	18,565	15,872
Paid related to:
Current period	(6,607)	(3,732)
Prior period	(12,047)	(11,557)
Total paid	(18,654)	(15,289)
Balance, end of period	$ 43,597	$ 41,751