Allowance for Loan and Lease Loss and Credit Quality (Internal Risk Rating By Loan Class) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	$ 18,321,142	$ 17,508,663
Loans and leases	18,321,142	17,508,663	$ 17,355,240
GNMA Loans past due by 90 days, but not yet repurchased	16,300
Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	$ 17,850,298	$ 17,012,351
Percentage of impaired loans	6.80%	8.10%
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	$ 156,264	$ 183,632
Percentage of impaired loans	1.70%	6.50%
Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	$ 234,592	$ 239,642
Percentage of impaired loans	91.50%	82.50%
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	$ 10,575	$ 12,214
Percentage of impaired loans		2.90%
Loss
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	6,554	$ 6,850
Impaired
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	62,859	53,974
Commercial real estate | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,401,679	3,330,442
Commercial real estate | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,593,395	2,599,055
Commercial real estate | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,964,851	2,858,956
Commercial real estate | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	464,690	463,625
Commercial real estate | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	165,956	142,984
Commercial real estate | Pass/Watch | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,298,489	3,205,241
Commercial real estate | Pass/Watch | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,476,143	2,466,247
Commercial real estate | Pass/Watch | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,937,224	2,828,370
Commercial real estate | Pass/Watch | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	461,099	458,328
Commercial real estate | Pass/Watch | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	157,548	134,491
Commercial real estate | Special Mention | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	41,571	55,194
Commercial real estate | Special Mention | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	53,530	75,189
Commercial real estate | Special Mention | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	11,217	11,903
Commercial real estate | Special Mention | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	1,712
Commercial real estate | Special Mention | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Commercial real estate | Substandard | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	41,523	48,699
Commercial real estate | Substandard | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	51,533	46,781
Commercial real estate | Substandard | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	12,514	14,687
Commercial real estate | Substandard | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,500	2,494
Commercial real estate | Substandard | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,189	1,189
Commercial real estate | Doubtful | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	145	1,368
Commercial real estate | Doubtful | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	653	972
Commercial real estate | Doubtful | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Commercial real estate | Doubtful | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Commercial real estate | Doubtful | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Commercial real estate | Loss | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,168	546
Commercial real estate | Loss | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,472	1,653
Commercial real estate | Loss | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Commercial real estate | Loss | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Commercial real estate | Loss | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Commercial real estate | Impaired | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	18,783	19,394
Commercial real estate | Impaired | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	10,064	8,213
Commercial real estate | Impaired | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,896	3,996
Commercial real estate | Impaired | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,091	1,091
Commercial real estate | Impaired | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	7,219	7,304
Commercial | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,686,597	1,508,780
Commercial | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,153,409	1,116,259
Commercial | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,082,651	950,588
Commercial | Pass/Watch | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,638,555	1,458,699
Commercial | Pass/Watch | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,097,943	1,063,305
Commercial | Pass/Watch | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,058,839	927,378
Commercial | Special Mention | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	14,510	15,716
Commercial | Special Mention | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	20,194	10,565
Commercial | Special Mention | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	6,700	5,614
Commercial | Substandard | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	16,137	24,678
Commercial | Substandard | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	30,323	37,387
Commercial | Substandard | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	5,849	6,866
Commercial | Doubtful | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	10	119
Commercial | Doubtful | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	3
Commercial | Doubtful | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	9,767	9,752
Commercial | Loss | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	802	347
Commercial | Loss | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	244
Commercial | Loss | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,222	978
Commercial | Impaired | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	16,583	9,221
Commercial | Impaired | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	4,949	4,755
Commercial | Impaired | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	274	0
Residential | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,021,331	2,887,971
Residential | Mortgage, net | Financing Receivables, Equal to Greater than 90 Days Past Due | GNMA Loans
Financing Receivable, Recorded Investment [Line Items]
GNMA Loans past due by 90 days, but not yet repurchased	16,300	10,900
Residential | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,056,848	1,011,844
Residential | Pass/Watch | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,948,765	2,830,547
Residential | Pass/Watch | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,050,235	1,006,647
Residential | Special Mention | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,770	1,803
Residential | Special Mention | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,150	1,490
Residential | Substandard | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	68,481	53,607
Residential | Substandard | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,962	2,727
Residential | Doubtful | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Residential | Doubtful | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Residential | Loss | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,315	2,014
Residential | Loss | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	501	980
Residential | Impaired | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Residential | Impaired | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Consumer & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	729,735	638,159
Consumer & other, net | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	725,458	633,098
Consumer & other, net | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,622	4,446
Consumer & other, net | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	581	527
Consumer & other, net | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Consumer & other, net | Loss
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	74	88
Consumer & other, net | Impaired
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	$ 0	$ 0