Allowance for Loan and Lease Loss and Credit Quality (Internal Risk Rating By Loan Class) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	$ 16,387,934	$ 15,327,732	$ 15,259,201
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	9,147,374		8,996,699
Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	3,148,288	3,290,610
Owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2,655,340	2,633,864
Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2,961,609	2,638,618
Construction & Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	287,757	258,722
Residential Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	94,380	81,846
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	3,091,902		2,956,620
Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	1,398,346	1,396,089
LOC & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	1,014,523	1,029,620
Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	679,033	523,114
Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	3,650,515		2,938,387
Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2,740,228	2,233,735
Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	910,287	852,478
Consumer & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	498,143	389,036	$ 367,495
Pass/Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	$ 15,869,688	$ 14,729,544
Percentage of impaired loans	4.00%	5.60%
Pass/Watch [Member] | Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	$ 2,947,350	$ 3,027,777
Pass/Watch [Member] | Owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2,505,149	2,475,944
Pass/Watch [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2,935,017	2,610,039
Pass/Watch [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	279,830	248,547
Pass/Watch [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	84,548	68,789
Pass/Watch [Member] | Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	1,342,019	1,346,148
Pass/Watch [Member] | LOC & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	982,591	991,209
Pass/Watch [Member] | Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	669,200	513,104
Pass/Watch [Member] | Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2,725,712	2,215,956
Pass/Watch [Member] | Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	903,813	846,277
Pass/Watch [Member] | Consumer & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	494,459	385,754
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	$ 211,424	$ 213,806
Percentage of impaired loans	4.00%	15.10%
Special Mention [Member] | Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	$ 96,196	$ 99,556
Special Mention [Member] | Owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	57,875	58,425
Special Mention [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	6,668	9,583
Special Mention [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	3,705	4,081
Special Mention [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	402	963
Special Mention [Member] | Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	25,180	12,661
Special Mention [Member] | LOC & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	9,168	17,665
Special Mention [Member] | Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2,546	2,554
Special Mention [Member] | Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2,776	2,330
Special Mention [Member] | Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	3,609	3,271
Special Mention [Member] | Consumer & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	3,299	2,717
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	$ 225,599	$ 261,399
Percentage of impaired loans	91.70%	77.90%
Substandard [Member] | Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	$ 93,975	$ 123,350
Substandard [Member] | Owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	77,522	81,567
Substandard [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	16,405	15,177
Substandard [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	3,131	5,003
Substandard [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	1,453	2,419
Substandard [Member] | Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	8,051	17,901
Substandard [Member] | LOC & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	19,588	6,399
Substandard [Member] | Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2,206	3,809
Substandard [Member] | Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2,206	4,497
Substandard [Member] | Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	871	1,079
Substandard [Member] | Consumer & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	191	198
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	$ 5,941	$ 4,863
Percentage of impaired loans	0.30%	0.10%
Doubtful [Member] | Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	$ 309	$ 821
Doubtful [Member] | Owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	818	309
Doubtful [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Doubtful [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Doubtful [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Doubtful [Member] | Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	241	198
Doubtful [Member] | LOC & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2	280
Doubtful [Member] | Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	4,571	3,255
Doubtful [Member] | Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Doubtful [Member] | Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Doubtful [Member] | Consumer & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Loss [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	14,839	$ 15,548
Percentage of impaired loans		1.30%
Loss [Member] | Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	151	$ 0
Loss [Member] | Owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	2,136	1,674
Loss [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Loss [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Loss [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Loss [Member] | Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	302	224
Loss [Member] | LOC & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	18	88
Loss [Member] | Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	510	392
Loss [Member] | Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	9,534	10,952
Loss [Member] | Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	1,994	1,851
Loss [Member] | Consumer & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	194	367
Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	60,443	102,572
Impaired [Member] | Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	10,307	39,106
Impaired [Member] | Owner Occupied Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	11,840	15,945
Impaired [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	3,519	3,819
Impaired [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	1,091	1,091
Impaired [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	7,977	9,675
Impaired [Member] | Term [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	22,553	18,957
Impaired [Member] | LOC & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	3,156	13,979
Impaired [Member] | Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Impaired [Member] | Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Impaired [Member] | Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	0	0
Impaired [Member] | Consumer & Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and leases, net	$ 0	$ 0