Acquisitions - Cummins-American Corp. (Details) - USD ($) $ / shares in Units, $ in Thousands			9 Months Ended
	May 31, 2021	May 28, 2021	Sep. 30, 2022	Dec. 31, 2021
Merger agreement
Goodwill			$ 317,873	$ 317,873
Consideration paid:
Goodwill			317,873	$ 317,873
CAC
Merger agreement
Shares received in business combination (in shares)	444.4783
Per share cash consideration entitled (in dollars per share)	$ 14,173.96
Special cash dividend		$ 60,000
Additional consideration paid in the form of a special dividend payment to CAC shareholders (in dollars per share)		$ 12,087.58
Goodwill	$ 6,337
Pre-tax acquisition expenses			$ 800
Assets acquired
Cash and cash equivalents	298,637
Securities	702,367
Portfolio loans, net of ACL	430,470
Premises and equipment	17,034
Other intangible assets	17,340
Mortgage servicing rights	629
Other assets	8,176
Total assets acquired	1,474,653
Liabilities assumed
Deposits	1,315,671
Other borrowings	16,651
Other liabilities	19,205
Total liabilities assumed	1,351,527
Net assets acquired	123,126
Consideration paid:
Cash	70,358
Common stock	59,105
Total consideration paid	129,463
Goodwill	6,337
Fair value of PCD financial assets	60,500
Gross contractual amounts receivable relating to the PCD financial assets	65,200
Contractual cash flows specific to the PCD financial assets will not be collected	$ 4,200