Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
OPERATING ACTIVITIES
Net income	$ 182,547	$ 243,519
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	36,250	6,900
Net amortization of premiums and discounts from acquisition	531	736
Depreciation and amortization	30,063	26,194
Amortization of debt issuance costs	438	225
Deferred income tax (benefit) expense	(10,649)	584
Net (increase) decrease in trading securities and other earning assets	(10,907)	22,229
Losses (gains) on investment securities, net	4,424	(60,198)
Gains on sales of assets	(4,360)	(3,184)
Amortization of securities premiums, net of discount accretion	21,892	22,964
Originations of loans held for sale	(31,862)	(21,131)
Gains on sales of loans held for sale, net	(608)	(609)
Proceeds from sales of loans held for sale	30,629	22,267
Equity-based compensation	9,174	11,902
Changes in:
Accrued income	(1,156)	(13,871)
Accrued expenses and taxes	16,139	(68,434)
Other assets and liabilities, net	(117,137)	215,716
Net cash provided by operating activities	155,408	405,809
Securities held to maturity:
Maturities, calls and principal repayments	214,861	223,317
Purchases	(149,912)	(851,840)
Securities available for sale:
Sales	68	0
Maturities, calls and principal repayments	843,812	725,027
Purchases	(502,731)	(1,151,486)
Equity securities with readily determinable fair values:
Sales		17,081
Purchases	(118)	(700)
Equity securities without readily determinable fair values:
Sales	4,790	13
Maturities, calls and principal repayments	300,874	83
Purchases	(356,646)	(16,232)
Payment on low-income housing tax credit investment commitments	(23,110)	(22,096)
Net increase in loans	(1,456,857)	(1,889,693)
Net decrease in fed funds sold and resell agreements	638,759	160,898
Net cash activity from acquisitions and divestitures	(793)	257,767
Net decrease in interest-bearing balances due from other financial institutions	60,091	38,596
Purchases of premises and equipment	(17,091)	(16,889)
Proceeds from sales of premises and equipment	4,369	6,644
Net cash used in investing activities	(439,634)	(2,519,510)
FINANCING ACTIVITIES
Net decrease in demand and savings deposits	(1,395,026)	(4,042,398)
Net increase (decrease) in time deposits	2,276,354	(298,259)
Net decrease in fed funds purchased and repurchase agreements	(171,584)	(577,152)
Proceeds from short-term debt	32,006,000
Repayment of short-term debt	(30,206,000)
Cash dividends paid	(36,871)	(35,790)
Proceeds from exercise of stock options and sales of treasury shares	997	1,029
Purchases of treasury stock	(7,902)	(31,806)
Net cash provided by (used in) financing activities	2,465,968	(4,984,376)
Increase (decrease) in cash and cash equivalents	2,181,742	(7,098,077)
Cash and cash equivalents at beginning of period	1,557,874	9,214,564
Cash and cash equivalents at end of period	3,739,616	2,116,487
Supplemental disclosures:
Income tax payments	49,656	54,785
Total interest payments	371,211	31,239
Noncash disclosures:
Acquisition of low-income housing tax credit investments	34,831	27,490
Commitment to fund low-income housing tax credit investments	$ 34,831	27,490
Transfer of loans to other real estate owned		12,313
Transfer of securities from available-for-sale to held-to-maturity		$ 3,593,711