Deposits (Additional Information About Corporation's Deposits) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Money market deposits obtained through brokers'		$ 24,500
Deposits from the Certificate of Deposit Account Registry Service (CDARS) deposits	2,723	45,005
Deposits from foreign sources (primarily Mexico)	799,504	744,669
Deposits from certain directors, executive officers and their affiliates	$ 158,971	$ 115,837