Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest and dividend income
Loans, including fees	$ 244,187	$ 176,379	$ 90,613
Loans held-for-sale	91	130	165
Securities:
Taxable	37,940	31,566	8,168
Tax exempt	5,329	5,287	5,107
Dividends from FHLBC and FRBC stock	1,920	936	456
Interest bearing deposits with financial institutions	2,503	2,175	656
Total interest and dividend income	291,970	216,473	105,165
Interest expense
Savings, NOW, and money market deposits	8,761	1,900	961
Time deposits	6,636	1,448	1,510
Securities sold under repurchase agreements	93	40	82
Other short-term borrowings	18,774	480
Junior subordinated debentures	1,095	1,136	1,133
Subordinated debentures	2,185	2,185	1,610
Senior notes	2,408	2,682	2,692
Notes payable and other borrowings	87	446	462
Total interest expense	40,039	10,317	8,450
Net interest and dividend income	251,931	206,156	96,715
Provision for credit losses	16,501	6,550	4,326
Net interest and dividend income after provision for credit losses	235,430	199,606	92,389
Noninterest income
Mortgage servicing rights mark to market (loss) gain	(1,425)	3,177	1,261
Net gain on sales of mortgage loans	1,477	2,022	9,300
Securities (losses) gains, net	(4,148)	(944)	232
Change in cash surrender value of BOLI	2,120	718	1,390
Card related income	10,051	10,989	6,712
Other income	4,196	5,243	2,329
Total noninterest income	34,179	43,116	39,260
Noninterest expense
Salaries and employee benefits	88,566	86,573	57,691
Occupancy, furniture and equipment	14,437	14,992	13,548
Computer and data processing	7,277	15,795	7,936
FDIC insurance	2,705	2,401	975
Net teller & bill paying	2,115	3,730	874
General bank insurance	1,212	1,221	1,214
Amortization of core deposit intangible	2,461	2,626	644
Advertising expense	721	589	343
Card related expense	5,123	4,348	2,538
Legal fees	927	873	1,096
Consulting & management fees	2,415	2,425	5,005
Other real estate expense, net	399	130	151
Other expense	16,843	15,470	11,767
Total noninterest expense	145,201	151,173	103,782
Income before income taxes	124,408	91,549	27,867
Provision for income taxes	32,679	24,144	7,823
Net income	$ 91,729	$ 67,405	$ 20,044
Basic earnings per share	$ 2.05	$ 1.51	$ 0.66
Diluted earnings per share	2.02	1.49	0.65
Dividends declared per share	$ 0.20	$ 0.20	$ 0.16
Wealth management
Noninterest income
Service charges on deposits	$ 9,803	$ 9,887	$ 9,408
Service charges on deposits
Noninterest income
Service charges on deposits	9,817	9,562	5,403
Secondary mortgage fees
Noninterest income
Service charges on deposits	259	332	1,044
Mortgage servicing income
Noninterest income
Service charges on deposits	$ 2,029	$ 2,130	$ 2,181