Allowance for Loan and Lease Loss and Credit Quality (Internal Risk Rating By Loan Class) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	$ 21,520,794	$ 20,422,666
GNMA Loans, right to repurchase	5,200
Pass/Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	$ 21,121,686	$ 20,076,448
Percentage of impaired loans	3.30%	3.20%
Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	$ 219,705	$ 155,864
Percentage of impaired loans	13.60%	8.80%
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	$ 136,971	$ 127,651
Percentage of impaired loans	83.10%	88.00%
Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	$ 14,105	$ 14,667
Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	2,658	5,779
Impaired
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	25,669	42,257
Commercial real estate | Non-owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	3,495,555	3,573,065
Commercial real estate | Owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	2,566,299	2,480,371
Commercial real estate | Multifamily, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	3,479,986	3,304,763
Commercial real estate | Construction & development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	771,214	736,254
Commercial real estate | Residential development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	191,500	196,890
Commercial real estate | Pass/Watch | Non-owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	3,428,080	3,497,801
Commercial real estate | Pass/Watch | Owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	2,468,692	2,422,351
Commercial real estate | Pass/Watch | Multifamily, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	3,468,743	3,284,445
Commercial real estate | Pass/Watch | Construction & development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	741,050	734,318
Commercial real estate | Pass/Watch | Residential development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	191,500	196,890
Commercial real estate | Special Mention | Non-owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	35,036	38,346
Commercial real estate | Special Mention | Owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	69,676	28,447
Commercial real estate | Special Mention | Multifamily, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	8,850	11,481
Commercial real estate | Special Mention | Construction & development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	30,164	0
Commercial real estate | Special Mention | Residential development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial real estate | Substandard | Non-owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	19,100	23,234
Commercial real estate | Substandard | Owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	23,057	22,136
Commercial real estate | Substandard | Multifamily, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	2,393	4,539
Commercial real estate | Substandard | Construction & development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	1,936
Commercial real estate | Substandard | Residential development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial real estate | Doubtful | Non-owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial real estate | Doubtful | Owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	80	54
Commercial real estate | Doubtful | Multifamily, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial real estate | Doubtful | Construction & development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial real estate | Doubtful | Residential development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial real estate | Loss | Non-owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	160	122
Commercial real estate | Loss | Owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	327
Commercial real estate | Loss | Multifamily, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial real estate | Loss | Construction & development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial real estate | Loss | Residential development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial real estate | Impaired | Non-owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	13,179	13,562
Commercial real estate | Impaired | Owner occupied term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	4,794	7,056
Commercial real estate | Impaired | Multifamily, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	4,298
Commercial real estate | Impaired | Construction & development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial real estate | Impaired | Residential development, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial | Term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	2,310,759	2,232,923
Commercial | Lines of credit & other, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	1,254,755	1,169,525
Commercial | Leases & equipment finance, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	1,485,753	1,330,155
Commercial | Pass/Watch | Term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	2,269,473	2,196,753
Commercial | Pass/Watch | Lines of credit & other, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	1,190,456	1,103,677
Commercial | Pass/Watch | Leases & equipment finance, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	1,451,038	1,296,235
Commercial | Special Mention | Term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	10,752	15,519
Commercial | Special Mention | Lines of credit & other, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	44,219	42,831
Commercial | Special Mention | Leases & equipment finance, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	7,199	8,571
Commercial | Substandard | Term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	25,498	5,670
Commercial | Substandard | Lines of credit & other, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	18,995	20,639
Commercial | Substandard | Leases & equipment finance, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	9,906	8,754
Commercial | Doubtful | Term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	2	53
Commercial | Doubtful | Lines of credit & other, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	227	313
Commercial | Doubtful | Leases & equipment finance, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	13,796	14,247
Commercial | Loss | Term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	4	69
Commercial | Loss | Lines of credit & other, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Commercial | Loss | Leases & equipment finance, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	2,006	1,931
Commercial | Impaired | Term, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	5,030	14,859
Commercial | Impaired | Lines of credit & other, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	858	2,065
Commercial | Impaired | Leases & equipment finance, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	1,808	417
Residential | Mortgage, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	4,245,674	3,635,073
Residential | Mortgage, net | Financing Receivables, Equal to Greater than 90 Days Past Due | GNMA Loans
Financing Receivable, Credit Quality Indicator [Line Items]
GNMA Loans, right to repurchase	5,200	8,900
Residential | Home equity loans & lines, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	1,224,578	1,176,477
Residential | Pass/Watch | Mortgage, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	4,201,253	3,588,976
Residential | Pass/Watch | Home equity loans & lines, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	1,220,793	1,172,040
Residential | Special Mention | Mortgage, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	8,034	5,169
Residential | Special Mention | Home equity loans & lines, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	2,487	1,878
Residential | Substandard | Mortgage, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	36,214	38,766
Residential | Substandard | Home equity loans & lines, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	1,012	1,418
Residential | Doubtful | Mortgage, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Residential | Doubtful | Home equity loans & lines, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Residential | Loss | Mortgage, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	173	2,162
Residential | Loss | Home equity loans & lines, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	286	1,141
Residential | Impaired | Mortgage, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Residential | Impaired | Home equity loans & lines, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Consumer & other, net
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	494,721	587,170
Consumer & other, net | Pass/Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	490,608	582,962
Consumer & other, net | Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	3,288	3,622
Consumer & other, net | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	796	559
Consumer & other, net | Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	0	0
Consumer & other, net | Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	29	27
Consumer & other, net | Impaired
Financing Receivable, Credit Quality Indicator [Line Items]
Loans by credit quality	$ 0	$ 0