Allowance for Loan and Lease Loss and Credit Quality (Activity In The Allowance For Loan And Lease Losses) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period, allowance				$ 133,984				$ 130,322	$ 133,984	$ 130,322
Charge-offs									(55,919)	(49,923)
Recoveries									15,289	11,911
(Recapture) provision	$ 12,928	$ 11,997	$ 10,657	11,672	$ 13,171	$ 13,091	$ 10,589	4,823	47,254	41,674	$ 36,589
Balance, end of period, allowance	140,608				133,984				140,608	133,984	130,322
Allowance for loans and leases:
Collectively evaluated for impairment, allowance												$ 137,160	$ 129,418
Individually evaluated for impairment, allowance												535	867
Loans acquired with deteriorated credit quality, allowance												35,286	31,976
Total	140,608			133,984	133,984			130,322	133,984	130,322	130,322	140,608	133,984	$ 130,322
Financing Receivable, Allowance for Credit Loss, Loans And Leases [Abstract]
Collectively evaluated for impairment, non-covered loans and leases												18,831,095	17,174,303
Individually evaluated for impairment, non-covered loans and leases												59,976	53,974
Loans acquired with deteriorated credit quality, non-covered loans and leases												1,132,217	918,612
Total												19,080,184	17,508,663	16,866,536
Receivables Acquired with Deteriorated Credit Quality
Allowance for loans and leases:
Loans acquired with deteriorated credit quality, allowance												2,913	3,699
Financing Receivable, Allowance for Credit Loss, Loans And Leases [Abstract]
Loans acquired with deteriorated credit quality, non-covered loans and leases												189,113	280,386
Commercial Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period, allowance				47,795				54,293	47,795	54,293
Charge-offs									(2,407)	(3,137)
Recoveries									3,068	1,958
(Recapture) provision									(2,691)	(5,319)
Balance, end of period, allowance	45,765				47,795				45,765	47,795	54,293
Allowance for loans and leases:
Collectively evaluated for impairment, allowance												43,186	44,205
Individually evaluated for impairment, allowance												531	859
Total	45,765			47,795	47,795			54,293	47,795	54,293	54,293	45,765	47,795	54,293
Financing Receivable, Allowance for Credit Loss, Loans And Leases [Abstract]
Collectively evaluated for impairment, non-covered loans and leases												9,592,471	9,124,422
Individually evaluated for impairment, non-covered loans and leases												31,999	39,998
Total												9,773,752	9,395,062
Commercial Real Estate | Receivables Acquired with Deteriorated Credit Quality
Allowance for loans and leases:
Loans acquired with deteriorated credit quality, allowance												2,048	2,731
Financing Receivable, Allowance for Credit Loss, Loans And Leases [Abstract]
Loans acquired with deteriorated credit quality, non-covered loans and leases												149,282	230,642
Commercial
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period, allowance				58,840				47,487	58,840	47,487
Charge-offs									(44,511)	(35,545)
Recoveries									8,163	4,995
(Recapture) provision									40,813	41,903
Balance, end of period, allowance	63,305				58,840				63,305	58,840	47,487
Allowance for loans and leases:
Collectively evaluated for impairment, allowance												62,912	58,515
Individually evaluated for impairment, allowance												4	8
Total	63,305			58,840	58,840			47,487	58,840	47,487	47,487	63,305	58,840	47,487
Financing Receivable, Allowance for Credit Loss, Loans And Leases [Abstract]
Collectively evaluated for impairment, non-covered loans and leases												4,246,535	3,555,660
Individually evaluated for impairment, non-covered loans and leases												27,977	13,976
Total												4,278,663	3,575,627
Commercial | Receivables Acquired with Deteriorated Credit Quality
Allowance for loans and leases:
Loans acquired with deteriorated credit quality, allowance												389	317
Financing Receivable, Allowance for Credit Loss, Loans And Leases [Abstract]
Loans acquired with deteriorated credit quality, non-covered loans and leases												4,151	5,991
Residential
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period, allowance				17,946				22,017	17,946	22,017
Charge-offs									(985)	(1,885)
Recoveries									764	1,028
(Recapture) provision									1,635	(3,214)
Balance, end of period, allowance	19,360				17,946				19,360	17,946	22,017
Allowance for loans and leases:
Collectively evaluated for impairment, allowance												18,912	17,353
Individually evaluated for impairment, allowance												0	0
Total	19,360			17,946	17,946			22,017	17,946	22,017	22,017	19,360	17,946	22,017
Financing Receivable, Allowance for Credit Loss, Loans And Leases [Abstract]
Collectively evaluated for impairment, non-covered loans and leases												4,260,258	3,856,658
Individually evaluated for impairment, non-covered loans and leases												0	0
Total												4,295,482	3,899,815
Residential | Receivables Acquired with Deteriorated Credit Quality
Allowance for loans and leases:
Loans acquired with deteriorated credit quality, allowance												448	593
Financing Receivable, Allowance for Credit Loss, Loans And Leases [Abstract]
Loans acquired with deteriorated credit quality, non-covered loans and leases												35,224	43,157
Consumer & Other, Net
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period, allowance				9,403				6,525	9,403	6,525
Charge-offs									(8,016)	(9,356)
Recoveries									3,294	3,930
(Recapture) provision									7,497	8,304
Balance, end of period, allowance	12,178				9,403				12,178	9,403	6,525
Allowance for loans and leases:
Collectively evaluated for impairment, allowance												12,150	9,345
Individually evaluated for impairment, allowance												0	0
Total	$ 12,178			$ 9,403	$ 9,403			$ 6,525	$ 9,403	$ 6,525	$ 6,525	12,178	9,403	$ 6,525
Financing Receivable, Allowance for Credit Loss, Loans And Leases [Abstract]
Collectively evaluated for impairment, non-covered loans and leases												731,831	637,563
Individually evaluated for impairment, non-covered loans and leases												0	0
Total												732,287	638,159
Consumer & Other, Net | Receivables Acquired with Deteriorated Credit Quality
Allowance for loans and leases:
Loans acquired with deteriorated credit quality, allowance												28	58
Financing Receivable, Allowance for Credit Loss, Loans And Leases [Abstract]
Loans acquired with deteriorated credit quality, non-covered loans and leases												$ 456	$ 596