Portfolio Loans- Distribution of portfolio loans (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	$ 7,670,114		$ 7,188,998
ACL	(90,722)	$ (88,757)	(87,887)	$ (92,802)	$ (95,410)	$ (101,048)
Portfolio loans, net	7,579,392		7,101,111
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	1,945,893		1,943,886
ACL	(23,695)	(23,359)	(23,855)	(24,406)	(24,356)	(23,866)
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	3,278,684		3,119,807
ACL	(37,799)	(37,182)	(38,249)	(39,831)	(39,974)	(46,230)
Real estate construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	499,560		385,996
ACL	(5,971)	(5,669)	(5,102)	(6,121)	(7,599)	(8,193)
Retail real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	1,643,099		1,512,976
ACL	(18,620)	(17,984)	(17,589)	(19,352)	(20,505)	(21,992)
Retail other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio loans	302,878		226,333
ACL	$ (4,637)	$ (4,563)	$ (3,092)	$ (3,092)	$ (2,976)	$ (767)