Loans (Summary Of Loan Portfolio) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Loans [Line Items]
Loans, net of unearned income, excluding covered loans	$ 13,749,996	$ 12,896,602	$ 12,516,892
Covered loans	275,154	346,431	454,602
Total loans	14,025,150	13,243,033	12,971,494
Total loans, net of unearned income, excluding covered loans, percentage	98.00%	97.00%	96.00%
Covered loans, percentage	2.00%	3.00%	4.00%
Total loans, percentage	100.00%	100.00%	100.00%
Commercial Portfolio Segment [Member]
Loans [Line Items]
Loans, net of unearned income, excluding covered loans	3,640,430	3,253,687	3,119,931
Total loans, net of unearned income, excluding covered loans, percentage	26.00%	25.00%	24.00%
Commercial Real Estate Portfolio Segment [Member]
Loans [Line Items]
Loans, net of unearned income, excluding covered loans	4,353,472	4,230,035	4,094,628
Total loans, net of unearned income, excluding covered loans, percentage	31.00%	32.00%	31.00%
Home equity
Loans [Line Items]
Loans, net of unearned income, excluding covered loans	713,642	719,137	758,260
Total loans, net of unearned income, excluding covered loans, percentage	5.00%	5.00%	6.00%
Residential Portfolio Segment [Member]
Loans [Line Items]
Loans, net of unearned income, excluding covered loans	451,905	434,992	384,961
Total loans, net of unearned income, excluding covered loans, percentage	3.00%	3.00%	3.00%
Premium finance receivables | Commercial Insurance Loans [Member]
Loans [Line Items]
Loans, net of unearned income, excluding covered loans	2,378,529	2,167,565	2,165,734
Total loans, net of unearned income, excluding covered loans, percentage	17.00%	16.00%	16.00%
Premium finance receivables | Premium Finance Receivables Life Insurance [Member]
Loans [Line Items]
Loans, net of unearned income, excluding covered loans	2,051,645	1,923,698	1,821,147
Total loans, net of unearned income, excluding covered loans, percentage	15.00%	15.00%	14.00%
Consumer and other
Loans [Line Items]
Loans, net of unearned income, excluding covered loans	$ 160,373	$ 167,488	$ 172,231
Total loans, net of unearned income, excluding covered loans, percentage	1.00%	1.00%	2.00%