Financial data pertaining to the different trusts (Parenthetical) (Detail) (Fixed Rate 500 Percent Until December 2013 And 900 Percent Thereafter Junior Subordinated Deferrable Interest Debentures With No Stated Maturity [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Fixed Rate 500 Percent Until December 2013 And 900 Percent Thereafter Junior Subordinated Deferrable Interest Debentures With No Stated Maturity [Member]
Debt Disclosure [Line Items]
Junior subordinates debentures, carrying value	$ 0	[1]	$ 531,540	[1]
Junior subordinates debentures, aggregate liquidation amount			936,000
Debt Instrument Unamortized Discount			$ 404,460

[1] The debentures are perpetual and may be redeemed by the Corporation at any time, subject to the consent of the Board of Governors of the Federal Reserve System. The discount on the debentures was being amortized over an estimated 30-year term that started in August 2009. During the quarter ended June 30, 2014, in connection with the repayment of these Notes completed on July 2, 2014, the Corporation accelerated the related amortization of the discount and deferred costs amounting to $414.1 million, which is reflected as interest expense in the consolidated statement of operations. The effective interest rate, including the discount accretion, was approximately 16% at December 31, 2013.