Loans (Schedule Of Loans By Portfolio Segment) (Details) - USD ($)		Jun. 30, 2015		Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		$ 16,936,772,000	[1]		$ 16,230,166,000	$ 15,795,709,000
Allowance for loan losses		221,351,000		$ 228,328,000	232,448,000	243,628,000	$ 247,246,000	$ 253,809,000
Total net loans		16,715,421,000			15,997,718,000	15,552,081,000
Commercial Financial And Industrial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		9,832,563,000			9,007,286,000	8,402,836,000
Allowance for loan losses		78,750,000		67,652,000	67,011,000	68,591,000	72,732,000	86,446,000
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		1,400,715,000			1,277,717,000	1,231,513,000
Allowance for loan losses		21,492,000		17,665,000	18,574,000	15,821,000	15,523,000	10,603,000
Consumer Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	[2]	4,870,271,000			5,048,071,000	5,218,930,000
Allowance for loan losses		85,457,000		109,245,000	113,011,000	118,037,000	123,409,000	126,785,000
Permanent Mortgage Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		487,679,000			538,961,000	594,001,000
Allowance for loan losses		22,377,000		20,186,000	19,122,000	23,727,000	22,521,000	22,491,000
Credit Card And Other Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		345,544,000			358,131,000	348,429,000
Allowance for loan losses		13,275,000		$ 13,580,000	14,730,000	17,452,000	$ 13,061,000	$ 7,484,000
Restricted And Secured Consumer Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		$ 66,400,000			$ 76,800,000	$ 84,400,000

[1] June 30, 2015 includes $28.3 million of held-to-maturity consumer mortgage loans secured by residential real estate in process of foreclosure.

[2] (a) Balances as of June 30, 2015 and 2014, and December 31, 2014 include $ 66 .4 million, $ 84.4 million, and $ 76.8 million of restricted real estate loans, respectively. See Note 13 - Variable Interest Entities for additional information.