CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities
Net income	$ 187,481	$ 186,097
Adjustments to reconcile net income to net cash provided by operating activities:
Provision (benefit) for credit losses	21,300	(1,564)
Depreciation, amortization and accretion, net	32,425	44,142
Deferred income tax (benefit) provision	(13,322)	13,807
Stock-based compensation	7,163	7,718
Other losses	1,243	2,780
Originations of loans held for sale	(11,483)	(14,243)
Proceeds from sales of loans held for sale	12,613	13,452
Change in assets and liabilities:
Net decrease in other assets	20,495	7,348
Net (decrease) increase in other liabilities	(44,095)	62,054
Net cash provided by operating activities	213,820	321,591
Available-for-sale securities:
Proceeds from maturities and principal repayments	345,798	752,306
Proceeds from calls and sales	25,236	1,080
Purchases		(938,268)
Held-to-maturity securities:
Proceeds from maturities and principal repayments	238,722	254,157
Proceeds from calls	7,950	395
Purchases		(79,470)
Other investments:
Proceeds from sales	78,746	5,496
Purchases	(102,639)	(29,514)
Loans:
Net increase in loans and leases resulting from originations and principal repayments	(214,539)	(521,025)
Purchases of loans	(48,911)	(225,844)
Proceeds from bank-owned life insurance	5,632
Purchases of premises, equipment and software	(8,283)	(10,747)
Other	313	(2,994)
Net cash provided by (used in) investing activities	328,025	(794,428)
Cash flows from financing activities
Net (decrease) increase in deposits	(177,540)	275,592
Proceeds from long-term borrowings	500,000
Net decrease in other short-term borrowings	(75,000)
Dividends paid	(99,468)	(99,475)
Stock tendered for payment of withholding taxes	(3,196)	(3,561)
Proceeds from employee stock purchase plan	163	224
Common stock repurchased		(9,478)
Net cash provided by financing activities	144,959	163,302
Net increase (decrease) in cash and cash equivalents	686,804	(309,535)
Cash and cash equivalents at beginning of period	526,624	1,258,469
Cash and cash equivalents at end of period	1,213,428	948,934
Supplemental disclosures
Interest paid	173,712	21,006
Income taxes paid, net of income tax refunds	50,098	23,471
Noncash investing and financing activities:
Operating lease right-of-use assets obtained in exchange for new lease obligations	3,239	5,603
Transfers to loans and leases from loans held for sale		834
Transfers to loans held for sale from loans and leases	1,133
Obligation to fund low-income housing partnerships	$ 25,836	3,569
Transfers of securities from available-for-sale to held-to-maturity		$ 4,550,748