Commitments And Contingencies (Summary Of Financial Instruments Outstanding) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Commitments to grant loans, Contract Amount	$ 360,726	$ 243,458
Unfunded commitments under lines of credit, Contract Amount	1,924,173	1,773,601
Commercial and standby letters of credit, Contract Amount	$ 42,905	$ 49,530

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant