CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities
Net income	$ 186,097	$ 208,713
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	(1,564)	(39,000)
Depreciation, amortization and accretion, net	44,142	41,835
Deferred income tax provision	13,807	7,321
Stock-based compensation	7,718	10,158
Other losses (gains)	2,780	(1,438)
Originations of loans held for sale	(14,243)	(83,050)
Proceeds from sales of loans held for sale	13,452	94,907
Net gains on sales of loans originated for investment and held for sale		(2,691)
Net gains on investment securities		(102)
Change in assets and liabilities:
Net decrease (increase) in other assets	7,348	(38,108)
Net increase in other liabilities	62,054	98,108
Net cash provided by operating activities	321,591	296,653
Available-for-sale securities:
Proceeds from maturities and principal repayments	752,306	1,371,213
Proceeds from calls and sales	1,080	3,555
Purchases	(938,268)	(3,403,074)
Held-to-maturity securities:
Proceeds from maturities and principal repayments	254,157
Proceeds from calls	395
Purchases	(79,470)
Other investments:
Proceeds from sales	5,496	16,790
Purchases	(29,514)	(70,797)
Loans:
Net (increase) decrease in loans and leases resulting from originations and principal repayments	(521,025)	652,354
Proceeds from sales of loans originated for investment		2,200
Purchases of loans	(225,844)	(238,445)
Proceeds from bank-owned life insurance		7,903
Purchases of premises, equipment and software	(10,747)	(15,174)
Proceeds from sales of premises and equipment		3,861
Proceeds from sales of other real estate owned	176
Other	(3,170)	(3,701)
Net cash used in investing activities	(794,428)	(1,673,315)
Cash flows from financing activities
Net increase in deposits	275,592	2,892,280
Repayment of long-term borrowings		(10)
Dividends paid	(99,475)	(100,889)
Stock tendered for payment of withholding taxes	(3,561)	(3,086)
Proceeds from employee stock purchase plan	224
Common stock repurchased	(9,478)	(53,495)
Net cash provided by financing activities	163,302	2,734,800
Net (decrease) increase in cash and cash equivalents	(309,535)	1,358,138
Cash and cash equivalents at beginning of period	1,258,469	1,040,944
Cash and cash equivalents at end of period	948,934	2,399,082
Supplemental disclosures
Interest paid	21,006	18,879
Income taxes paid, net of income tax refunds	23,471	53,742
Noncash investing and financing activities:
Operating lease right-of-use assets obtained in exchange for new lease obligations	5,603	29,632
Transfers (to) from loans and leases (from) to loans held for sale		1,839
Transfers to loans and leases from loans held for sale	(834)
Obligation to fund low-income housing partnerships	3,569	$ 15,314
Transfers of securities from available-for-sale to held-to-maturity	$ 4,550,748