Allowance for Loan and Lease Loss and Credit Quality (Non-Accrual Loans And Loans Past Due) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 73,626	$ 69,651
Non-Accrual	44,573	27,765
Current & Other	18,559,563	17,411,247
Loans by credit quality	18,677,762	17,508,663
GNMA Loans past due by 90 days, but not yet repurchased	12,300
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current & Other	206,600	280,400
Greater than 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	12,033	12,587
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	20,218	17,838
Greater than 90 Days and Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	41,375	39,226
Commercial real estate | Non-owner occupied term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,804	2,792
Non-Accrual	3,500	2,100
Current & Other	3,469,939	3,325,550
Loans by credit quality	3,475,243	3,330,442
Commercial real estate | Owner occupied term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,485	5,514
Non-Accrual	6,780	4,391
Current & Other	2,456,730	2,589,150
Loans by credit quality	2,467,995	2,599,055
Commercial real estate | Multifamily, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	325	0
Non-Accrual	366	476
Current & Other	2,992,512	2,858,480
Loans by credit quality	2,993,203	2,858,956
Commercial real estate | Construction & development, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Non-Accrual	1,091	0
Current & Other	520,575	463,625
Loans by credit quality	521,666	463,625
Commercial real estate | Residential development, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Non-Accrual	6,153	0
Current & Other	180,247	142,984
Loans by credit quality	186,400	142,984
Commercial real estate | Greater than 30 to 59 Days Past Due | Non-owner occupied term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	258	718
Commercial real estate | Greater than 30 to 59 Days Past Due | Owner occupied term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,087	974
Commercial real estate | Greater than 30 to 59 Days Past Due | Multifamily, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Commercial real estate | Greater than 30 to 59 Days Past Due | Construction & development, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Commercial real estate | Greater than 30 to 59 Days Past Due | Residential development, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Commercial real estate | 60 to 89 Days Past Due | Non-owner occupied term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	947	1,027
Commercial real estate | 60 to 89 Days Past Due | Owner occupied term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,397	4,539
Commercial real estate | 60 to 89 Days Past Due | Multifamily, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	325	0
Commercial real estate | 60 to 89 Days Past Due | Construction & development, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Commercial real estate | 60 to 89 Days Past Due | Residential development, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Commercial real estate | Greater than 90 Days and Accruing | Non-owner occupied term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	599	1,047
Commercial real estate | Greater than 90 Days and Accruing | Owner occupied term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1	1
Commercial real estate | Greater than 90 Days and Accruing | Multifamily, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Commercial real estate | Greater than 90 Days and Accruing | Construction & development, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Commercial real estate | Greater than 90 Days and Accruing | Residential development, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Commercial | Term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,104	552
Non-Accrual	13,081	6,880
Current & Other	1,805,479	1,501,348
Loans by credit quality	1,819,664	1,508,780
Commercial | LOC & other, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,257	1,700
Non-Accrual	3,700	4,998
Current & Other	1,129,088	1,109,561
Loans by credit quality	1,134,045	1,116,259
Commercial | Leases and equipment finance, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	15,862	14,016
Non-Accrual	9,902	8,920
Current & Other	1,111,968	927,652
Loans by credit quality	1,137,732	950,588
Commercial | Greater than 30 to 59 Days Past Due | Term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	131	319
Commercial | Greater than 30 to 59 Days Past Due | LOC & other, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	583	1,673
Commercial | Greater than 30 to 59 Days Past Due | Leases and equipment finance, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,379	5,343
Commercial | 60 to 89 Days Past Due | Term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	973	233
Commercial | 60 to 89 Days Past Due | LOC & other, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	169	27
Commercial | 60 to 89 Days Past Due | Leases and equipment finance, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	8,072	6,865
Commercial | Greater than 90 Days and Accruing | Term, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Commercial | Greater than 90 Days and Accruing | LOC & other, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	505	0
Commercial | Greater than 90 Days and Accruing | Leases and equipment finance, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,411	1,808
Residential | Mortgage, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	40,556	36,827
Non-Accrual	0	0
Current & Other	3,053,805	2,851,144
Loans by credit quality	3,094,361	2,887,971
Residential | Home equity loans & lines, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	4,567	3,217
Non-Accrual	0	0
Current & Other	1,075,364	1,008,627
Loans by credit quality	1,079,931	1,011,844
Residential | Greater than 30 to 59 Days Past Due | Mortgage, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	10
Residential | Greater than 30 to 59 Days Past Due | Home equity loans & lines, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,235	289
Residential | 60 to 89 Days Past Due | Mortgage, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,024	3,114
Residential | 60 to 89 Days Past Due | Home equity loans & lines, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,309	848
Residential | Greater than 90 Days and Accruing | Mortgage, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	35,532	33,703
Residential | Greater than 90 Days and Accruing | Mortgage, net | GNMA Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
GNMA Loans past due by 90 days, but not yet repurchased	12,300	10,900
Residential | Greater than 90 Days and Accruing | Home equity loans & lines, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,023	2,080
Consumer & other, net
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,666	5,033
Non-Accrual	0	0
Current & Other	763,856	633,126
Loans by credit quality	767,522	638,159
Consumer & other, net | Greater than 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,360	3,261
Consumer & other, net | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,002	1,185
Consumer & other, net | Greater than 90 Days and Accruing
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 304	$ 587