Commitments and Contingencies - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	1 Months Ended
	Jul. 11, 2013	Aug. 02, 2013 Policies	Apr. 30, 2013 Ambac [Member]	Apr. 30, 2013 Segregated Account [Member]
Loss Contingencies [Line Items]
Minimum percentage of payments on permitted policy claims	25.00%
Number of policies considered for Supplemental Payments		14
Payment to settle the IRS dispute and related proceedings			$ 1,900	$ 100,000