Loans (Schedule Of Risk Category Of Loans By Class Of Loans) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	$ 3,574,089	$ 3,378,252
Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	3,350,475	3,175,333
Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	82,612	77,186
Commercial Real Estate [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	141,002	125,733
Construction [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	411,003	428,232
Construction [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	329,848	324,292
Construction [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	42,845	48,442
Construction [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	38,114	55,498
Construction [Member] | Doubtful [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	196
Total [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	5,863,479	5,631,550
Total [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	5,350,266	5,138,564
Total [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	221,183	217,759
Total [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	291,302	275,151
Total [Member] | Doubtful [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	728	76
Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	1,878,387	1,825,066
Commercial And Industrial [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	1,669,943	1,638,939
Commercial And Industrial [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	95,726	92,131
Commercial And Industrial [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	112,186	93,920
Commercial And Industrial [Member] | Doubtful [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	$ 532	$ 76