CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating activities:
Net income	$ 86,860	$ 100,794
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	7,373	8,014
Amortization of intangible assets	7,583	6,597
Net accretion on securities, loans and borrowings	(9,662)	(11,729)
Stock-based compensation	4,190	3,242
Provision for credit losses	6,944	(10,057)
Amortization of mortgage servicing rights	299	269
Unrealized loss (gain) on equity securities	20	(24)
Income from bank-owned life insurance policies	(944)	(981)
Net gain on sale of loans and other assets	(305)	(463)
Change in other assets and other liabilities	(3,443)	(7,585)
Net cash provided by operating activities	98,915	88,077
Investing activities:
Proceeds from maturities, calls, and paydowns of available-for-sale investment securities	86,423	151,994
Proceeds from maturities and redemptions of equity and other investment securities	464	2,648
Purchases of available-for-sale investment securities	(1,348,400)	(759,022)
Purchases of equity and other securities	(313)	(92)
Net (increase) decrease in loans	(335,796)	179,167
Cash received (paid) for acquisitions, net of cash acquired of $84,988 and $0, respectively	345	(2,900)
Purchases of premises and equipment, net	(4,979)	(5,689)
Real estate tax credit investments	(247)	(320)
Net cash used in investing activities	(1,602,503)	(434,214)
Financing activities:
Net (decrease) increase in deposits	(75,691)	1,114,051
Net increase in overnight Federal Reserve Bank borrowings	66,000	0
Net decrease in securities sold under agreement to repurchase, short-term	(100,965)	(89,121)
Payments on other Federal Home Loan Bank borrowings	(33)	(3,722)
Payments on subordinated debt held by unconsolidated subsidiary trusts	0	(77,320)
Issuance of common stock	799	8,669
Purchases of treasury stock	(16,498)	(128)
Increase in deferred compensation arrangements	120	128
Cash dividends paid	(46,453)	(45,162)
Withholding taxes paid on share-based compensation	(1,127)	(1,137)
Net cash (used in) provided by financing activities	(173,848)	906,258
Change in cash and cash equivalents	(1,677,436)	560,121
Cash and cash equivalents at beginning of period	1,875,064	1,645,805
Cash and cash equivalents at end of period	197,628	2,205,926
Supplemental disclosures of cash flow information:
Cash paid for interest	5,967	7,644
Cash paid for income taxes	25,247	22,482
Supplemental disclosures of noncash financing and investing activities:
Dividends declared and unpaid	23,264	22,768
Transfers from loans to other real estate	303	120
Acquisitions:
Fair value of assets acquired, excluding acquired cash and intangibles	483,438	199
Fair value of liabilities assumed	$ 544,950	$ 174