Loans and Allowance for Loan Losses (Schedule Of Allowances For Loan Losses And Recorded Investment In Loans) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	$ 307,560,000		$ 373,405,000
Allowance for loan losses of sold branches	(1,019,000)
Charge-offs	(22,275,000)		(67,119,000)
Recoveries	7,094,000		9,790,000
Provision for loan losses	9,511,000		35,696,000
Ending balance, allowance	300,871,000		351,772,000
Ending balance: individually evaluated for impairment, allowance	65,167,000		69,014,000
Ending balance: collectively evaluated for impairment, allowance	235,704,000		282,758,000
Total loans	20,187,440,000	[1]	19,389,439,000	[2]	20,086,660,000	[3]
Ending balance: individually evaluated for impairment, loans	754,303,000		984,516,000
Ending balance: collectively evaluated for impairment, loans	19,433,137,000		18,404,923,000
Deferred fees and costs, net	28,400,000		21,600,000		28,900,000
Commercial Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	127,012,000		167,926,000
Allowance for loan losses of sold branches	(281,000)
Charge-offs	(7,946,000)		(36,276,000)
Recoveries	2,227,000		3,602,000
Provision for loan losses	5,943,000		10,739,000
Ending balance, allowance	126,955,000		145,991,000
Ending balance: individually evaluated for impairment, allowance	42,894,000		44,252,000
Ending balance: collectively evaluated for impairment, allowance	84,061,000		101,739,000
Total loans	6,486,159,000	[1]	6,422,635,000	[2]
Ending balance: individually evaluated for impairment, loans	481,684,000		644,627,000
Ending balance: collectively evaluated for impairment, loans	6,004,475,000		5,778,008,000
Commercial and Industrial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	116,069,000		138,495,000
Allowance for loan losses of sold branches	(398,000)
Charge-offs	(8,036,000)		(19,218,000)
Recoveries	1,953,000		4,418,000
Provision for loan losses	18,758,000		10,962,000
Ending balance, allowance	128,346,000		134,657,000
Ending balance: individually evaluated for impairment, allowance	20,678,000		22,563,000
Ending balance: collectively evaluated for impairment, allowance	107,668,000		112,094,000
Total loans	10,062,376,000	[1]	9,540,141,000	[2]
Ending balance: individually evaluated for impairment, loans	220,376,000		272,756,000
Ending balance: collectively evaluated for impairment, loans	9,842,000,000		9,267,385,000
Retail [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	41,479,000		38,984,000
Allowance for loan losses of sold branches	(340,000)
Charge-offs	(6,293,000)		(11,625,000)
Recoveries	2,914,000		1,770,000
Provision for loan losses	7,810,000		13,995,000
Ending balance, allowance	45,570,000		43,124,000
Ending balance: individually evaluated for impairment, allowance	1,595,000		2,199,000
Ending balance: collectively evaluated for impairment, allowance	43,975,000		40,925,000
Total loans	3,638,905,000	[1]	3,426,663,000	[2]
Ending balance: individually evaluated for impairment, loans	52,243,000		67,133,000
Ending balance: collectively evaluated for impairment, loans	3,586,662,000		3,359,530,000
Unallocated [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	23,000,000		28,000,000
Allowance for loan losses of sold branches	0
Charge-offs	0		0
Recoveries	0		0
Provision for loan losses	(23,000,000)		0
Ending balance, allowance	0		28,000,000
Ending balance: individually evaluated for impairment, allowance	0		0
Ending balance: collectively evaluated for impairment, allowance	0		28,000,000
Total loans	0	[1]	0	[2]
Ending balance: individually evaluated for impairment, loans	0		0
Ending balance: collectively evaluated for impairment, loans	$ 0		$ 0

[1] Total before net deferred fees and costs of $28.4 million.

[2] Total before net deferred fees and costs of $21.6 million.

[3] Total before net deferred fees and costs of