Loans And Allowance For Loan Losses (Summary Of Loans, Net Of Unearned Income) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases	$ 4,439,493	$ 3,970,214
Loans, net of unearned income	8,137,719	6,856,667
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases	2,707,046	2,495,727
Commercial And Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases	1,602,314	1,363,692
Commercial Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases	130,133	110,795
Direct Installment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,178,530	1,029,187
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,092,228	670,936
Indirect Installment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	582,037	540,789
Consumer Lines Of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	805,494	607,280
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	39,937	38,261
Originated Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases	4,133,905	3,970,214
Loans, net of unearned income	7,237,391	6,856,667
Originated Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases	2,448,471	2,495,727
Loans, net of unearned income	2,448,471	2,495,727
Originated Loans [Member] | Commercial And Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases	1,555,301	1,363,692
Loans, net of unearned income	1,555,301	1,363,692
Originated Loans [Member] | Commercial Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases	130,133	110,795
Loans, net of unearned income	130,133	110,795
Originated Loans [Member] | Direct Installment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,108,865	1,029,187
Originated Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	653,826	670,936
Originated Loans [Member] | Indirect Installment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	568,324	540,789
Originated Loans [Member] | Consumer Lines Of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	732,534	607,280
Originated Loans [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	39,937	38,261
Acquired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases	305,588
Loans, net of unearned income	900,328	307,347
Acquired Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases	258,575
Loans, net of unearned income	258,575
Acquired Loans [Member] | Commercial And Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases	47,013
Loans, net of unearned income	47,013
Acquired Loans [Member] | Commercial Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total commercial loans and leases
Loans, net of unearned income
Acquired Loans [Member] | Direct Installment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	69,665
Acquired Loans [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	438,402
Acquired Loans [Member] | Indirect Installment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	13,713
Acquired Loans [Member] | Consumer Lines Of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	72,960
Acquired Loans [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income