Loans And Allowance For Loan Losses (Summary Of Consumer And Other Loans By Payment Activity) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Credit Quality [Line Items]
Non-Performing Loans	$ 96,164	$ 106,228
Loans, net of uneraned income	7,860,856	6,856,667
Direct Installment [Member]
Credit Quality [Line Items]
Loans, net of uneraned income	1,109,676	1,029,187
Residential Mortgage [Member]
Credit Quality [Line Items]
Loans, net of uneraned income	1,158,377	670,936
Indirect Installment [Member]
Credit Quality [Line Items]
Loans, net of uneraned income	577,903	540,789
Consumer Lines Of Credit [Member]
Credit Quality [Line Items]
Loans, net of uneraned income	741,509	607,280
Other [Member]
Credit Quality [Line Items]
Loans, net of uneraned income	37,962	38,261
Performing Financing Receivable [Member] | Direct Installment [Member]
Credit Quality [Line Items]
Performing Loans	1,102,467	1,022,025
Performing Financing Receivable [Member] | Residential Mortgage [Member]
Credit Quality [Line Items]
Performing Loans	1,148,257	661,392
Performing Financing Receivable [Member] | Indirect Installment [Member]
Credit Quality [Line Items]
Performing Loans	576,767	539,810
Performing Financing Receivable [Member] | Consumer Lines Of Credit [Member]
Credit Quality [Line Items]
Performing Loans	741,078	606,533
Performing Financing Receivable [Member] | Other [Member]
Credit Quality [Line Items]
Performing Loans	34,462	34,761
Nonperforming Financing Receivable [Member] | Direct Installment [Member]
Credit Quality [Line Items]
Non-Performing Loans	7,209	7,162
Nonperforming Financing Receivable [Member] | Residential Mortgage [Member]
Credit Quality [Line Items]
Non-Performing Loans	10,120	9,544
Nonperforming Financing Receivable [Member] | Indirect Installment [Member]
Credit Quality [Line Items]
Non-Performing Loans	1,136	979
Nonperforming Financing Receivable [Member] | Consumer Lines Of Credit [Member]
Credit Quality [Line Items]
Non-Performing Loans	431	747
Nonperforming Financing Receivable [Member] | Other [Member]
Credit Quality [Line Items]
Non-Performing Loans	$ 3,500	$ 3,500