Allowance for Loan and Lease Loss and Credit Quality (Internal Risk Rating By Loan Class) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	$ 20,953,371	$ 20,422,666
GNMA Loans, right to repurchase	5,400
Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	$ 20,563,922	$ 20,076,448
Percentage of impaired loans	3.30%	3.20%
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	$ 236,535	$ 155,864
Percentage of impaired loans	14.30%	8.80%
Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	$ 105,798	$ 127,651
Percentage of impaired loans	82.40%	88.00%
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	$ 16,579	$ 14,667
Loss
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,194	5,779
Impaired
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	27,343	42,257
Commercial real estate | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,537,084	3,573,065
Commercial real estate | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,396,674	2,480,371
Commercial real estate | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,341,547	3,304,763
Commercial real estate | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	732,932	736,254
Commercial real estate | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	199,421	196,890
Commercial real estate | Pass/Watch | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,455,860	3,497,801
Commercial real estate | Pass/Watch | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,314,355	2,422,351
Commercial real estate | Pass/Watch | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,331,275	3,284,445
Commercial real estate | Pass/Watch | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	731,015	734,318
Commercial real estate | Pass/Watch | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	199,421	196,890
Commercial real estate | Special Mention | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	51,231	38,346
Commercial real estate | Special Mention | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	59,795	28,447
Commercial real estate | Special Mention | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	6,838	11,481
Commercial real estate | Special Mention | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,917	0
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	17,143	23,234
Commercial real estate | Substandard | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	15,863	22,136
Commercial real estate | Substandard | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,434	4,539
Commercial real estate | Substandard | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	1,936
Commercial real estate | Substandard | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Commercial real estate | Doubtful | Non-owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	228	0
Commercial real estate | Doubtful | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	576	54
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	0	122
Commercial real estate | Loss | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	327
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	12,622	13,562
Commercial real estate | Impaired | Owner occupied term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	6,085	7,056
Commercial real estate | Impaired | Multifamily, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	4,298
Commercial real estate | Impaired | Construction & development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Commercial real estate | Impaired | Residential development, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Commercial | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,271,346	2,232,923
Commercial | Lines of credit & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,280,587	1,169,525
Commercial | Leases & equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,449,579	1,330,155
Commercial | Pass/Watch | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,222,485	2,196,753
Commercial | Pass/Watch | Lines of credit & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,202,892	1,103,677
Commercial | Pass/Watch | Leases & equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,415,475	1,296,235
Commercial | Special Mention | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	34,191	15,519
Commercial | Special Mention | Lines of credit & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	62,605	42,831
Commercial | Special Mention | Leases & equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	6,813	8,571
Commercial | Substandard | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	7,926	5,670
Commercial | Substandard | Lines of credit & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	13,762	20,639
Commercial | Substandard | Leases & equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	8,835	8,754
Commercial | Doubtful | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,090	53
Commercial | Doubtful | Lines of credit & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	405	313
Commercial | Doubtful | Leases & equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	14,280	14,247
Commercial | Loss | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	168	69
Commercial | Loss | Lines of credit & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	0	0
Commercial | Loss | Leases & equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,949	1,931
Commercial | Impaired | Term, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	5,486	14,859
Commercial | Impaired | Lines of credit & other, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	923	2,065
Commercial | Impaired | Leases & equipment finance, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	2,227	417
Residential | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,995,643	3,635,073
Residential | Mortgage, net | Financing Receivables, Equal to Greater than 90 Days Past Due | GNMA Loans
Financing Receivable, Recorded Investment [Line Items]
GNMA Loans, right to repurchase	5,400	8,900
Residential | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,215,215	1,176,477
Residential | Pass/Watch | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,950,673	3,588,976
Residential | Pass/Watch | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,210,910	1,172,040
Residential | Special Mention | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	7,840	5,169
Residential | Special Mention | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,981	1,878
Residential | Substandard | Mortgage, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	36,846	38,766
Residential | Substandard | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	1,565	1,418
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	284	2,162
Residential | Loss | Home equity loans & lines, net
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	759	1,141
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	533,343	587,170
Consumer & other, net | Pass/Watch
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	529,561	582,962
Consumer & other, net | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	3,324	3,622
Consumer & other, net | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	424	559
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	34	27
Consumer & other, net | Impaired
Financing Receivable, Recorded Investment [Line Items]
Loans by credit quality	$ 0	$ 0