Business Combinations - Summary of Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($)	Mar. 20, 2023	Mar. 31, 2024	Dec. 31, 2023
Assets
Goodwill		$ 196,461,000	$ 196,461,000
Blackhawk Bancorp, Inc
Assets
Goodwill		$ 50,097,000
Consideration paid
Consideration payable in cash	$ 1,928
Total consideration paid	93,510,000
Blackhawk Bancorp, Inc | Fair Value Adjustments
Assets
Cash and due from banks	55,600,000
Loans held for sale	3,222,000
Loans, net	722,866,000
Investment securities	377,969,000
Short-term investments	869,000
FHLB stock	1,737,000
Premises and equipment	12,366,000
Accrued interest receivable	4,029,000
Prepaid expenses	1,182,000
Other assets	20,742,000
Core deposit intangible	34,590,000
Income tax receivable	2,077,000
Deferred tax asset	22,152,000
Mortgage servicing rights	7,031,000
Total assets acquired	1,266,432,000
Liabilities
Deposits	1,194,972,000
Subordinated and Junior Subordinated debt	16,448,000
Accrued interest payable	1,091,000
Accrued and other liabilities	10,508,000
Total liabilities assumed	1,223,019,000
Net assets acquired	43,413,000
Consideration paid
Total consideration paid	93,510,000
Goodwill	$ 50,097,000