Summarized Activity in Liability for Unpaid Losses and Loss Adjustment Expenses (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Liability for Unpaid Claims and Claims Adjustment Expense, Adjustment of Opening Balance [Line Items]
Balance at beginning of period	$ 879,114	$ 971,377	$ 1,052,743
Ceded reinsurance receivables	240,566	283,652	407,195
Net balance at beginning of period	638,548	687,725	645,548
Incurred losses and loss adjustment expenses related to:
Current year	140,873	149,183	275,284
Prior years	(7,882)	4,445	3,400
Total incurred losses and loss adjustment expenses	132,991	153,628	278,684
Paid losses and loss adjustment expenses related to:
Current year	50,732	52,164	78,340
Prior years	133,832	150,641	158,167
Total paid losses and loss adjustment expenses	184,564	202,805	236,507
Net balance at end of period	586,975	638,548	687,725
Ceded reinsurance receivables	192,491	240,566	283,652
Balance at end of period	$ 779,466	$ 879,114	$ 971,377