Loans and Allowance for Loan Losses (Schedule Of Allowances For Loan Losses And Recorded Investment In Loans) (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013	Dec. 31, 2013
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	$ 277,783,000		$ 334,880,000	$ 307,560,000		$ 373,405,000
Allowance for loan losses of sold branches				(1,019,000)
Charge-offs	(22,761,000)		(30,253,000)	(87,117,000)		(145,288,000)
Recoveries	10,511,000		7,224,000	24,314,000		34,961,000
Provision for loan losses	3,843,000		6,761,000	25,638,000		55,534,000
Ending balance, allowance	269,376,000		318,612,000	269,376,000		318,612,000
Ending balance: individually evaluated for impairment, allowance	39,165,000		78,051,000	39,165,000		78,051,000
Ending balance: collectively evaluated for impairment, allowance	230,211,000		240,561,000	230,211,000		240,561,000
Total loans	20,617,415,000	[1]	19,736,612,000	20,617,415,000	[1]	19,736,612,000	20,086,660,000	[2]
Ending balance: individually evaluated for impairment, loans	537,540,000		881,953,000	537,540,000		881,953,000
Ending balance: collectively evaluated for impairment, loans	20,079,875,000		18,854,659,000	20,079,875,000		18,854,659,000
Deferred fees and costs, net	28,800,000		25,000,000	28,800,000		25,000,000	28,900,000
Commercial Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	104,394,000		138,329,000	127,646,000		167,926,000
Allowance for loan losses of sold branches				(281,000)
Charge-offs	(5,233,000)		(9,474,000)	(41,139,000)		(73,825,000)
Recoveries	3,099,000		2,766,000	8,318,000		11,861,000
Provision for loan losses	(271,000)		5,562,000	7,445,000		31,221,000
Ending balance, allowance	101,989,000		137,183,000	101,989,000		137,183,000
Ending balance: individually evaluated for impairment, allowance	22,107,000		50,737,000	22,107,000		50,737,000
Ending balance: collectively evaluated for impairment, allowance	79,882,000		86,446,000	79,882,000		86,446,000
Total loans	6,745,379,000	[1]	6,458,518,000	6,745,379,000	[1]	6,458,518,000
Ending balance: individually evaluated for impairment, loans	317,011,000		569,128,000	317,011,000		569,128,000
Ending balance: collectively evaluated for impairment, loans	6,428,368,000		5,889,390,000	6,428,368,000		5,889,390,000
Commercial and Industrial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	130,814,000		133,190,000	115,435,000		138,495,000
Allowance for loan losses of sold branches				(398,000)
Charge-offs	(11,306,000)		(13,871,000)	(26,896,000)		(44,104,000)
Recoveries	5,257,000		2,152,000	9,562,000		17,266,000
Provision for loan losses	78,000		(2,352,000)	27,140,000		7,462,000
Ending balance, allowance	124,843,000		119,119,000	124,843,000		119,119,000
Ending balance: individually evaluated for impairment, allowance	15,863,000		25,194,000	15,863,000		25,194,000
Ending balance: collectively evaluated for impairment, allowance	108,980,000		93,925,000	108,980,000		93,925,000
Total loans	10,017,075,000	[1]	9,705,425,000	10,017,075,000	[1]	9,705,425,000
Ending balance: individually evaluated for impairment, loans	172,860,000		259,764,000	172,860,000		259,764,000
Ending balance: collectively evaluated for impairment, loans	9,844,215,000		9,445,661,000	9,844,215,000		9,445,661,000
Retail [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	42,575,000		40,361,000	41,479,000		38,984,000
Allowance for loan losses of sold branches				(340,000)
Charge-offs	(6,222,000)		(6,908,000)	(19,082,000)		(27,359,000)
Recoveries	2,155,000		2,306,000	6,434,000		5,834,000
Provision for loan losses	4,036,000		3,551,000	14,053,000		21,851,000
Ending balance, allowance	42,544,000		39,310,000	42,544,000		39,310,000
Ending balance: individually evaluated for impairment, allowance	1,195,000		2,120,000	1,195,000		2,120,000
Ending balance: collectively evaluated for impairment, allowance	41,349,000		37,190,000	41,349,000		37,190,000
Total loans	3,854,961,000	[1]	3,572,669,000	3,854,961,000	[1]	3,572,669,000
Ending balance: individually evaluated for impairment, loans	47,669,000		53,061,000	47,669,000		53,061,000
Ending balance: collectively evaluated for impairment, loans	3,807,292,000		3,519,608,000	3,807,292,000		3,519,608,000
Unallocated [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	0		23,000,000	23,000,000		28,000,000
Allowance for loan losses of sold branches				0
Charge-offs	0		0	0		0
Recoveries	0		0	0		0
Provision for loan losses	0		0	(23,000,000)		(5,000,000)
Ending balance, allowance	0		23,000,000	0		23,000,000
Ending balance: individually evaluated for impairment, allowance	0		0	0		0
Ending balance: collectively evaluated for impairment, allowance	0		23,000,000	0		23,000,000
Total loans	0	[1]	0	0	[1]	0
Ending balance: individually evaluated for impairment, loans	0		0	0		0
Ending balance: collectively evaluated for impairment, loans	$ 0		$ 0	$ 0		$ 0

[1] Total before net deferred fees and costs of $28.8 million.

[2] Total before net deferred fees and costs of $28.9 million.