Loans and Allowance for Loan Losses (Schedule Of Allowances For Loan Losses And Recorded Investment In Loans) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	$ 252,496	$ 261,317
Charge-offs	(11,315)	(20,624)
Recoveries	3,958	8,281
Provision for loan losses	9,377	4,397
Ending balance, allowance	254,516	253,371
Ending balance: individually evaluated for impairment, allowance	32,973	29,006
Ending balance: collectively evaluated for impairment, allowance	221,543	224,365
Total loans	22,787,534	21,135,581	$ 22,459,664
Ending balance: individually evaluated for impairment, loans	297,785	408,685
Ending balance: collectively evaluated for impairment, loans	22,489,749	20,726,896
Deferred fees and costs, net	29,300	29,400	$ 30,100
Commercial Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	87,133	101,471
Charge-offs	(1,822)	(7,440)
Recoveries	1,293	3,941
Provision for loan losses	(2,047)	(3,764)
Ending balance, allowance	84,557	94,208
Ending balance: individually evaluated for impairment, allowance	17,603	18,558
Ending balance: collectively evaluated for impairment, allowance	66,954	75,650
Total loans	7,591,718	6,898,159
Ending balance: individually evaluated for impairment, loans	136,826	237,167
Ending balance: collectively evaluated for impairment, loans	7,454,892	6,660,992
Commercial and Industrial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	122,989	118,110
Charge-offs	(5,525)	(5,272)
Recoveries	1,264	2,266
Provision for loan losses	6,150	2,702
Ending balance, allowance	124,878	117,806
Ending balance: individually evaluated for impairment, allowance	14,033	9,411
Ending balance: collectively evaluated for impairment, allowance	110,845	108,395
Total loans	10,831,389	10,316,689
Ending balance: individually evaluated for impairment, loans	123,557	130,197
Ending balance: collectively evaluated for impairment, loans	10,707,832	10,186,492
Retail [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance, allowance	42,374	41,736
Charge-offs	(3,968)	(7,912)
Recoveries	1,401	2,074
Provision for loan losses	5,274	5,459
Ending balance, allowance	45,081	41,357
Ending balance: individually evaluated for impairment, allowance	1,337	1,037
Ending balance: collectively evaluated for impairment, allowance	43,744	40,320
Total loans	4,364,427	3,920,733
Ending balance: individually evaluated for impairment, loans	37,402	41,321
Ending balance: collectively evaluated for impairment, loans	$ 4,327,025	$ 3,879,412