Loans (Schedule Of Loans By Portfolio Segment) (Details) - USD ($)		Sep. 30, 2015		Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		$ 16,725,492,000	[1]		$ 16,230,166,000	$ 15,812,017,000
Allowance for loan losses		210,814,000		$ 221,351,000	232,448,000	238,641,000	$ 243,628,000	$ 253,809,000
Total net loans		16,514,678,000			15,997,718,000	15,573,376,000
Commercial Financial And Industrial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		9,610,295,000			9,007,286,000	8,477,329,000
Allowance for loan losses		71,463,000		78,750,000	67,011,000	69,870,000	68,591,000	86,446,000
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		1,488,044,000			1,277,717,000	1,278,394,000
Allowance for loan losses		25,348,000		21,492,000	18,574,000	15,450,000	15,821,000	10,603,000
Consumer Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	[2]	4,813,936,000			5,048,071,000	5,130,988,000
Allowance for loan losses		82,472,000		85,457,000	113,011,000	118,395,000	118,037,000	126,785,000
Permanent Mortgage Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		463,893,000			538,961,000	572,789,000
Allowance for loan losses		20,076,000		22,377,000	19,122,000	20,221,000	23,727,000	22,491,000
Credit Card And Other Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		349,324,000			358,131,000	352,517,000
Allowance for loan losses		11,455,000		$ 13,275,000	14,730,000	14,705,000	$ 17,452,000	$ 7,484,000
Restricted And Secured Consumer Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income		$ 59,300,000			$ 76,800,000	$ 81,100,000

[1] September 30, 2015 includes $30.7 million of held-to-maturity consumer mortgage loans secured by residential real estate in process of foreclosure.

[2] (a) Balances as of September 30, 2015 and 2014, and December 31, 2014 include $ 59. 3 million, $ 81 . 1 million, and $ 76.8 million of restricted real estate loans, respectively. See Note 13 - Variable Interest Entities for additional information.