CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities:
Net income	$ 98,218	$ 135,551
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	9,781	10,956
Amortization of intangible assets	10,948	11,420
Net amortization (accretion) on securities, loans and borrowings	3,675	(14,519)
Stock-based compensation	6,709	6,047
Gain on debt extinguishment	(242)	0
Provision for credit losses	7,130	12,005
Amortization of mortgage servicing rights	654	554
Loss on sales of investment securities	52,329	0
Unrealized loss on equity securities	99	24
Income from bank-owned life insurance policies	(1,762)	(1,543)
Net gain on sale of assets	(1,067)	(570)
Change in other assets and liabilities	(2,758)	(16,889)
Net cash provided by operating activities	183,714	143,036
Investing activities:
Proceeds from maturities, calls, and paydowns of available-for-sale investment securities	582,614	210,152
Proceeds from maturities, calls, and paydowns of held-to-maturity investment securities	72	0
Proceeds from maturities and redemptions of equity and other investment securities	20,960	2,247
Proceeds from sales of available-for-sale investment securities	733,789	0
Purchases of available-for-sale investment securities	0	(1,348,400)
Purchases of held-to-maturity investment securities	(23,933)	0
Purchases of equity and other securities	(4,542)	(6,108)
Net increase in loans	(660,031)	(735,072)
Cash (paid) received for acquisitions, net of cash acquired of $0 and $84,988, respectively	(8,301)	345
Proceeds from sales of premises, equipment and other assets	5,902	1,928
Purchases of premises and equipment	(13,889)	(10,014)
Real estate limited partnership investments	0	(247)
Net cash provided by (used in) investing activities	632,641	(1,885,169)
Financing activities:
Net increase in deposits	18,480	52,858
Net (decrease) increase in overnight borrowings	(768,400)	119,800
Net (decrease) increase in securities sold under agreement to repurchase, short-term	(16,400)	28,052
Proceeds from other Federal Home Loan Bank borrowings	300,000	0
Payments on and maturities of other Federal Home Loan Bank borrowings	(2,713)	(71)
Payments of contingent consideration for acquisitions	(1,214)	0
Redemption of subordinated notes payable	(3,000)	0
Proceeds from issuance of common stock	711	1,086
Purchases of treasury stock	(25,839)	(16,555)
Increase in deferred compensation arrangements	163	177
Cash dividends paid	(71,048)	(69,681)
Withholding taxes paid on share-based compensation	(1,184)	(1,206)
Net cash (used in) provided by financing activities	(570,444)	114,460
Change in cash and cash equivalents	245,911	(1,627,673)
Cash and cash equivalents at beginning of period	209,896	1,875,064
Cash and cash equivalents at end of period	455,807	247,391
Supplemental disclosures of cash flow information:
Cash paid for interest	64,147	11,793
Cash paid for income taxes	29,198	41,061
Supplemental disclosures of noncash financing and investing activities:
Dividends declared and unpaid	24,189	23,750
Transfers from loans to other real estate	232	303
Transfers from premises and equipment, net to other assets	1,948	5,113
Acquisitions:
Fair value of assets acquired, excluding acquired cash and intangibles	243	490,623
Fair value of liabilities assumed	18	543,507
Contingent consideration in exchange for acquired assets	$ 1,450	$ 0