Financial Guarantee Insurance Contracts - Estimated Future Amortization Expense for Insurance Intangible Asset (Detail) (Insurance Intangible Asset [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2014
Insurance Intangible Asset [Member]
Amortization Of Intangible Assets [Line Items]
2014	$ 98,796
2015	119,906
2016	109,388
2017	100,904
2018	94,857
Thereafter	$ 1,046,219