Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income	$ 11,712	$ 10,674	$ 9,737	$ 17,959
Adjustments to reconcile net income to net cash provided by operating activities:
Credit loss expense	4,685	696	26,418	2,290
Depreciation, amortization, and accretion			2,342	4,473
Net loss on sale of premises and equipment			61	40
Share-based compensation			734	604
Net gain on sale or call of debt securities available for sale			(48)	(49)
Net (gain) loss on sale of foreclosed assets, net			(45)	1
Writedown of foreclosed assets			164	0
Net gain on sale of loans held for sale			(2,696)	(821)
Origination of loans held for sale			179,415	50,900
Proceeds from sales of loans held for sale			175,463	49,429
Increase in cash surrender value of bank-owned life insurance			(786)	(862)
Increase in deferred income taxes, net			(6,680)	(76)
Change in:
Other assets			(9,761)	1,028
Other liabilities			13,226	(4,866)
Net cash provided by operating activities			28,714	18,250
Cash flows from investing activities:
Proceeds from sales of debt securities available for sale			22,146	125,414
Proceeds from maturities and calls of debt securities available for sale			78,311	49,699
Purchases of debt securities available for sale			(452,716)	(112,256)
Proceeds from maturities and calls of debt securities held to maturity			0	3,117
Net increase in loans, net of unearned income			(142,475)	(5,482)
Purchases of premises and equipment			(803)	(1,242)
Proceeds from sale of foreclosed assets			2,637	763
Proceeds from sale of premises and equipment			2	0
Net cash acquired in business acquisition			0	37,054
Proceeds from sale of intangible assets			0	99
Net cash (used in) provided by investing activities			(492,898)	97,166
Cash flows from financing activities:
Deposits			536,589	33,449
Short-term borrowings			22,875	(38,354)
Long-term debt			(41,713)	(27,250)
Taxes paid relating to the release/lapse of restriction on RSUs			(139)	(88)
Dividends paid			(7,098)	(4,926)
Payment of stock issuance costs			0	(323)
Repurchase of common stock			(2,604)	(2,895)
Net cash provided by (used in) financing activities			507,910	(40,387)
Net increase in cash and cash equivalents			43,726	75,029
Cash and cash equivalents:
Beginning of Period			73,484	45,480
Ending balance	117,210	120,509	117,210	120,509
Supplemental disclosures of cash flow information:
Cash paid during the period for interest			18,039	15,493
Cash paid during the period for income taxes			3,505	1,405
Supplemental schedule of non-cash investing and financing activities:
Transfer of loans to foreclosed assets, net			15	1,384
Investment securities purchased but not settled			30,192	0
Initial recognition of operating lease right of use asset	4,067		4,067
Initial recognition of operation lease liability	5,036		5,036
Noncash assets acquired:
Goodwill	93,977		93,977
ATBancorp
Noncash assets acquired:
Debt securities available for sale	0	99,056	0	99,056
Loans	0	1,137,880	0	1,137,880
Premises and equipment	0	19,213	0	19,213
Goodwill	0	28,722	0	28,722
Bank-owned life insurance	0	18,759	0	18,759
Foreclosed assets	0	3,767	0	3,767
Other assets	0	17,657	0	17,657
Total noncash assets acquired			0	1,353,284
Liabilities assumed:
Deposits	0	1,079,094	0	1,079,094
Short-term borrowings	0	60,761	0	60,761
FHLB borrowings	0	82,771	0	82,771
Junior subordinated notes issued to capital trusts	0	17,557	0	17,557
Subordinated debentures	0	10,873	0	10,873
Other liabilities	0	25,613	0	25,613
Total liabilities assumed			0	1,276,669
ATBancorp | Core deposit intangible
Noncash assets acquired:
Core deposit intangible	$ 0	$ 28,230	$ 0	$ 28,230