Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
OPERATING ACTIVITIES
Net income	$ 331,509	$ 274,522
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	28,900	11,500
Net amortization of premiums and discounts from acquisition	1,057	390
Depreciation and amortization	39,751	41,736
Amortization of debt issuance costs	338	338
Deferred income tax benefit	(6,332)	(3,403)
Net decrease (increase) in trading securities and other earning assets	17,485	(47,336)
Gains on investment securities, net	(58,853)	(3,609)
Gains on sales of assets	(3,206)	(2,605)
Amortization of securities premiums, net of discount accretion	34,617	42,014
Originations of loans held for sale	(34,340)	(112,448)
Gains on sales of loans held for sale, net	(910)	(4,294)
Proceeds from sales of loans held for sale	33,657	118,805
Equity-based compensation	16,741	14,096
Net tax benefit related to equity compensation plans	2,253	1,813
Changes in:
Accrued income	(22,756)	12,891
Accrued expenses and taxes	(38,518)	(60,986)
Other assets and liabilities, net	283,716	78,938
Net cash provided by operating activities	625,109	362,362
Securities held to maturity:
Maturities, calls and principal repayments	350,282	142,169
Purchases	(946,974)	(216,979)
Securities available for sale:
Sales	0	295,546
Maturities, calls and principal repayments	935,626	1,336,507
Purchases	(1,128,812)	(3,720,734)
Equity securities with readily determinable fair values:
Sales	28,417	72,801
Maturities, calls and principal repayments		2
Purchases	(1,019)	(1,058)
Equity securities without readily determinable fair values:
Sales	13	14
Maturities, calls and principal repayments	148	2,501
Purchases	(22,529)	(20,936)
Payment on low-income housing tax credit investment commitments	(30,238)	(12,202)
Net increase in loans	(2,802,349)	(408,476)
Net decrease in fed funds sold and resell agreements	499,808	558,231
Net cash activity from acquisitions and divestitures	257,767	18,431
Net (increase) decrease in interest-bearing balances due from other financial institutions	(20,653)	10,318
Purchases of premises and equipment	(34,346)	(20,703)
Proceeds from sales of premises and equipment	6,432	1,666
Purchases of bank-owned and company-owned life insurance		(100,000)
Net cash used in investing activities	(2,908,427)	(2,062,902)
FINANCING ACTIVITIES
Net (decrease) increase in demand and savings deposits	(4,038,619)	4,475,973
Net increase (decrease) in time deposits	18,326	(291,414)
Net (decrease) increase in fed funds purchased and repurchase agreements	(924,267)	184,843
Proceeds from long-term debt	110,000
Payment of debt issuance costs	(2,032)
Cash dividends paid	(53,666)	(48,816)
Proceeds from exercise of stock options and sales of treasury shares	1,336	14,776
Purchases of treasury stock	(31,806)	(4,269)
Net cash (used in) provided by financing activities	(4,920,728)	4,331,093
(Decrease) increase in cash and cash equivalents	(7,204,046)	2,630,553
Cash and cash equivalents at beginning of period	9,214,564	3,497,566
Cash and cash equivalents at end of period	2,010,518	6,128,119
Supplemental disclosures:
Income tax payments	80,053	69,612
Total interest payments	91,564	37,967
Noncash disclosures:
Acquisition of low-income housing tax credit investments	28,409	30,182
Commitment to fund low-income housing tax credit investments	28,409	$ 30,182
Transfer of loans to other real estate owned	12,381
Transfer of securities from available-for-sale to held-to-maturity	$ 3,741,208