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Loans and Leases and Allowance for Credit Losses - Major classifications of loan and lease portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Classifications of loans
Total loans	$ 11,760,346	$ 11,370,815
Less ACL - loans	(102,532)	(137,010)	$ (62,089)	$ (61,203)
Loans and leases, net	11,657,814	11,233,805
Loans receivable
Classifications of loans
Total loans	11,760,346	11,370,815
Loans receivable \| Commercial
Classifications of loans
Total loans	8,930,556	8,960,888
Loans receivable \| Commercial \| Owner occupied commercial real estate
Classifications of loans
Total loans	2,321,685	2,090,443
Less ACL - loans	(14,282)	(20,673)	(11,404)	(12,207)
Loans receivable \| Commercial \| Income producing commercial real estate
Classifications of loans
Total loans	2,600,858	2,540,750
Less ACL - loans	(24,156)	(41,737)	(12,306)	(11,073)
Loans receivable \| Commercial \| Commercial & industrial
Classifications of loans
Total loans	1,910,162	2,498,560
Less ACL - loans	(16,592)	(22,019)	(5,266)	(4,802)
Loans receivable \| Commercial \| PPP loans included in commercial & industrial
Classifications of loans
Total loans	88,300	646,000
Loans receivable \| Commercial \| Construction
Classifications of loans
Total loans	1,014,830	967,305
Less ACL - loans	(9,956)	(10,952)	(9,668)	(10,337)
Loans receivable \| Commercial \| Equipment financing
Classifications of loans
Total loans	1,083,021	863,830
Less ACL - loans	(16,290)	(16,820)	(7,384)	(5,452)
Loans receivable \| Residential \| Residential mortgage
Classifications of loans
Total loans	1,637,885	1,284,920
Less ACL - loans	(12,390)	(15,341)	(8,081)	(8,295)
Loans receivable \| Residential \| HELOC
Classifications of loans
Total loans	694,034	697,117
Less ACL - loans	(6,568)	(8,417)	(4,575)	(4,752)
Loans receivable \| Residential \| Construction
Classifications of loans
Total loans	359,815	281,430
Less ACL - loans	(1,847)	(764)	(2,504)	(2,433)
Loans receivable \| Consumer
Classifications of loans
Total loans	138,056	146,460
Less ACL - loans	$ (451)	$ (287)	$ (901)	$ (853)