Loans And Allowance For Loan Losses (Schedule Of Allowances For Loan Losses And Recorded Investment In Loans) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				$ 261,317				$ 307,560	$ 261,317	$ 307,560	$ 373,405
Allowance for loan losses of sold loans										(1,019)
Charge-offs									(57,339)	(113,538)	(179,953)
Recoveries									29,508	34,483	44,510
Provision for loan losses	$ 5,021	$ 2,956	$ 6,636	4,397	$ 8,193	$ 3,843	$ 12,284	9,511	19,010	33,831	69,598
Ending balance	252,496				261,317				252,496	261,317	307,560
Ending balance: individually evaluated for impairment	30,435				33,476				30,435	33,476	67,997
Ending balance: collectively evaluated for impairment	222,061				227,841				222,061	227,841	239,563
Ending balance: total loans	22,459,664				21,128,489				22,459,664	21,128,489	20,086,660
Ending balance: individually evaluated for impairment	301,800				442,148				301,800	442,148	836,554
Ending balance: collectively evaluated for impairment	22,157,864				20,686,341				22,157,864	20,686,341	19,250,106
Deferred fees and costs, net	30,099				30,790				30,099	30,790	28,900
Commercial Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				101,471				127,646	101,471	127,646	167,926
Allowance for loan losses of sold loans										(281)
Charge-offs									(13,998)	(49,716)	(87,031)
Recoveries									13,644	11,787	17,068
Provision for loan losses									(13,984)	12,035	29,683
Ending balance	87,133				101,471				87,133	101,471	127,646
Ending balance: individually evaluated for impairment	18,969				21,755				18,969	21,755	46,787
Ending balance: collectively evaluated for impairment	68,164				79,716				68,164	79,716	80,859
Ending balance: total loans	7,375,466				6,926,602				7,375,466	6,926,602	6,506,976
Ending balance: individually evaluated for impairment	157,958				251,536				157,958	251,536	538,730
Ending balance: collectively evaluated for impairment	7,217,508				6,675,066				7,217,508	6,675,066	5,968,246
Commercial And Industrial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				118,110				115,435	118,110	115,435	138,495
Allowance for loan losses of sold loans										(398)
Charge-offs									(22,583)	(38,941)	(58,936)
Recoveries									8,611	14,628	19,918
Provision for loan losses									18,851	27,386	15,958
Ending balance	122,989				118,110				122,989	118,110	115,435
Ending balance: individually evaluated for impairment	10,477				10,451				10,477	10,451	20,018
Ending balance: collectively evaluated for impairment	112,512				107,659				112,512	107,659	95,417
Ending balance: total loans	10,791,432				10,267,719				10,791,432	10,267,719	9,931,451
Ending balance: individually evaluated for impairment	105,599				146,026				105,599	146,026	242,862
Ending balance: collectively evaluated for impairment	10,685,833				10,121,693				10,685,833	10,121,693	9,688,589
Retail [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				41,736				41,479	41,736	41,479	38,984
Allowance for loan losses of sold loans										(340)
Charge-offs									(20,758)	(24,881)	(33,986)
Recoveries									7,253	8,068	7,524
Provision for loan losses									14,143	17,410	28,957
Ending balance	42,374				41,736				42,374	41,736	41,479
Ending balance: individually evaluated for impairment	989				1,270				989	1,270	1,192
Ending balance: collectively evaluated for impairment	41,385				40,466				41,385	40,466	40,287
Ending balance: total loans	4,292,766				3,934,168				4,292,766	3,934,168	3,648,233
Ending balance: individually evaluated for impairment	38,243				44,586				38,243	44,586	54,962
Ending balance: collectively evaluated for impairment	4,254,523				3,889,582				4,254,523	3,889,582	3,593,271
Unallocated [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance				$ 0				$ 23,000	0	23,000	28,000
Allowance for loan losses of sold loans										0
Charge-offs									0	0	0
Recoveries									0	0	0
Provision for loan losses									0	(23,000)	(5,000)
Ending balance	0				0				0	0	23,000
Ending balance: individually evaluated for impairment	0				0				0	0	0
Ending balance: collectively evaluated for impairment	0				0				0	0	23,000
Ending balance: total loans	0				0				0	0	0
Ending balance: individually evaluated for impairment	0				0				0	0	0
Ending balance: collectively evaluated for impairment	$ 0				$ 0				$ 0	$ 0	$ 0