Loans (Schedule Of Loans By Portfolio Segment) (Details) - USD ($)		Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	[1]	$ 17,574,994,000	$ 17,686,502,000	$ 16,732,123,000
Allowance for loan losses		204,034,000	210,242,000	228,328,000	$ 232,448,000
Total net loans		17,370,960,000	17,476,260,000	16,503,795,000
Commercial Financial And Industrial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		10,239,183,000	10,436,390,000	9,638,355,000
Allowance for loan losses		80,887,000	73,637,000	67,652,000	67,011,000
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		1,848,569,000	1,674,935,000	1,320,897,000
Allowance for loan losses		25,626,000	25,159,000	17,665,000	18,574,000
Consumer Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	[2]	4,690,230,000	4,766,518,000	4,922,817,000
Allowance for loan losses		67,321,000	80,614,000	109,245,000	113,011,000
Permanent Mortgage Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		442,791,000	454,123,000	511,708,000
Allowance for loan losses		18,754,000	18,947,000	20,186,000	19,122,000
Credit Card And Other Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		354,221,000	354,536,000	338,346,000
Allowance for loan losses		11,446,000	11,885,000	13,580,000	$ 14,730,000
Restricted And Secured Consumer Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		$ 47,800,000	$ 52,800,000	$ 71,600,000

[1] March 31, 2016 and 2015 and December 31, 2015 include $31.2 million , $28.0 million and $29.7 million, respectively, of held-to-maturity consumer mortgage loans secured by residential real estate properties in process of foreclosure.

[2] Balances as of March 31, 2016 and 2015, and December 31, 2015, include $ 47.8 million , $ 71 . 6 million, and $ 52 .8 million of restricted real estate loans, respectively. See Note 13 - Variable Interest Entities for additional information.