Allowance for Loan and Lease Loss and Credit Quality (Internal Risk Rating By Loan Class) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
GNMA Loans past due by 90 days, but not yet repurchased	$ 5,300
Loans by credit quality	17,829,638	$ 17,508,663
Loans and leases	17,829,638	17,508,663	$ 16,955,583
Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	$ 17,324,637	$ 17,012,351
Percentage of impaired loans	7.80%	8.10%
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	$ 193,344	$ 183,632
Percentage of impaired loans	1.90%	6.50%
Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	$ 239,114	$ 239,642
Percentage of impaired loans	84.90%	82.50%
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	$ 9,168	$ 12,214
Percentage of impaired loans	5.40%	2.90%
Loss
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	$ 7,665	$ 6,850
Impaired
Financing Receivable, Recorded Investment [Line Items]
Loans and leases	55,710	53,974
Commercial real estate | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,410,914	3,330,442
Commercial real estate | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,584,183	2,599,055
Commercial real estate | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,885,164	2,858,956
Commercial real estate | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	471,007	463,625
Commercial real estate | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	145,479	142,984
Commercial real estate | Pass/Watch | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,289,051	3,205,241
Commercial real estate | Pass/Watch | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,457,239	2,466,247
Commercial real estate | Pass/Watch | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,844,856	2,828,370
Commercial real estate | Pass/Watch | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	465,728	458,328
Commercial real estate | Pass/Watch | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	137,066	134,491
Commercial real estate | Special Mention | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	55,328	55,194
Commercial real estate | Special Mention | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	66,413	75,189
Commercial real estate | Special Mention | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	21,805	11,903
Commercial real estate | Special Mention | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,689	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	48,403	48,699
Commercial real estate | Substandard | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	46,341	46,781
Commercial real estate | Substandard | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	14,597	14,687
Commercial real estate | Substandard | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,499	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	248	1,368
Commercial real estate | Doubtful | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	183	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	1,180	546
Commercial real estate | Loss | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,579	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	16,704	19,394
Commercial real estate | Impaired | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	11,428	8,213
Commercial real estate | Impaired | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,906	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	7,224	7,304
Commercial | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,620,311	1,508,780
Commercial | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,114,160	1,116,259
Commercial | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,000,376	950,588
Commercial | Pass/Watch | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,569,166	1,458,699
Commercial | Pass/Watch | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,059,396	1,063,305
Commercial | Pass/Watch | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	975,994	927,378
Commercial | Special Mention | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	11,841	15,716
Commercial | Special Mention | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	16,742	10,565
Commercial | Special Mention | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	10,001	5,614
Commercial | Substandard | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	29,328	24,678
Commercial | Substandard | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	31,939	37,387
Commercial | Substandard | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	4,885	6,866
Commercial | Doubtful | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	890	119
Commercial | Doubtful | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2	3
Commercial | Doubtful | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	7,845	9,752
Commercial | Loss | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	275	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	1,186	978
Commercial | Impaired | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	8,811	9,221
Commercial | Impaired | LOC & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	6,081	4,755
Commercial | Impaired | Leases and equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	465	0
Residential | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,916,924	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	5,300	10,900
Residential | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,015,138	1,011,844
Residential | Pass/Watch | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,855,718	2,830,547
Residential | Pass/Watch | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,008,705	1,006,647
Residential | Special Mention | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,428	1,803
Residential | Special Mention | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,781	1,490
Residential | Substandard | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	55,751	53,607
Residential | Substandard | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,350	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	2,027	2,014
Residential | Loss | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	302	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	665,982	638,159
Consumer & other, net | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	661,718	633,098
Consumer & other, net | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,316	4,446
Consumer & other, net | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	832	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	116	88
Consumer & other, net | Impaired
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	$ 0	$ 0