Allowance for Loan and Lease Loss and Credit Quality (Non-Accrual Loans And Loans Past Due) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 38,886	$ 32,171
Greater than 90 Days and Accruing	9,967	7,512
Nonaccrual	30,989	52,041
Current & Other	16,318,059	15,243,520
Total Loans and Leases	16,387,934	15,327,732	$ 15,259,201
Purchased impaired non-covered loans	448,100	562,900
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	9,147,374		8,996,699
Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	8,740	735
Greater than 90 Days and Accruing	177	283
Nonaccrual	2,769	8,957
Current & Other	3,136,779	3,280,918
Total Loans and Leases	3,148,288	3,290,610
Owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	6,742	2,651
Greater than 90 Days and Accruing	596	0
Nonaccrual	6,195	8,292
Current & Other	2,642,403	2,622,921
Total Loans and Leases	2,655,340	2,633,864
Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	512
Greater than 90 Days and Accruing	0	0
Nonaccrual	0	300
Current & Other	2,961,609	2,637,806
Total Loans and Leases	2,961,609	2,638,618
Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	918	1,091
Greater than 90 Days and Accruing	0	0
Nonaccrual	0	0
Current & Other	286,839	257,631
Total Loans and Leases	287,757	258,722
Residential Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	12	6,155
Greater than 90 Days and Accruing	12	0
Nonaccrual	0	0
Current & Other	94,368	75,691
Total Loans and Leases	94,380	81,846
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	3,091,902		2,956,620
Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	189	1,343
Greater than 90 Days and Accruing	81	3
Nonaccrual	17,038	19,097
Current & Other	1,381,119	1,375,649
Total Loans and Leases	1,398,346	1,396,089
LOC & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	512	4,015
Greater than 90 Days and Accruing	6	1,223
Nonaccrual	797	8,825
Current & Other	1,013,214	1,016,780
Total Loans and Leases	1,014,523	1,029,620
Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,644	3,872
Greater than 90 Days and Accruing	892	695
Nonaccrual	4,190	5,084
Current & Other	669,199	514,158
Total Loans and Leases	679,033	523,114
Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans and Leases	3,650,515		2,938,387
Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	7,754	5,521
Greater than 90 Days and Accruing	6,079	4,289
Nonaccrual	0	655
Current & Other	2,732,474	2,227,559
Total Loans and Leases	2,740,228	2,233,735
Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,734	3,375
Greater than 90 Days and Accruing	1,773	749
Nonaccrual	0	615
Current & Other	905,553	848,488
Total Loans and Leases	910,287	852,478
Consumer & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,641	2,901
Greater than 90 Days and Accruing	351	270
Nonaccrual	0	216
Current & Other	494,502	385,919
Total Loans and Leases	498,143	389,036	$ 367,495
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	15,858	18,284
Financing Receivables, 30 to 59 Days Past Due [Member] | Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,299	452
Financing Receivables, 30 to 59 Days Past Due [Member] | Owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,156	2,304
Financing Receivables, 30 to 59 Days Past Due [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	918	1,091
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	6,155
Financing Receivables, 30 to 59 Days Past Due [Member] | Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	7	1,098
Financing Receivables, 30 to 59 Days Past Due [Member] | LOC & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	172	1,637
Financing Receivables, 30 to 59 Days Past Due [Member] | Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,546	1,482
Financing Receivables, 30 to 59 Days Past Due [Member] | Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	8
Financing Receivables, 30 to 59 Days Past Due [Member] | Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,152	1,924
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,608	2,133
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	13,061	6,375
Financing Receivables, 60 to 89 Days Past Due [Member] | Non-owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,264	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Owner Occupied Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	990	347
Financing Receivables, 60 to 89 Days Past Due [Member] | Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	512
Financing Receivables, 60 to 89 Days Past Due [Member] | Construction & Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Term [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	101	242
Financing Receivables, 60 to 89 Days Past Due [Member] | LOC & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	334	1,155
Financing Receivables, 60 to 89 Days Past Due [Member] | Leases and Equipment Finance [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,206	1,695
Financing Receivables, 60 to 89 Days Past Due [Member] | Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,675	1,224
Financing Receivables, 60 to 89 Days Past Due [Member] | Home Equity Loans & Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,809	702
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 682	$ 498