Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating activities
Net (loss) income from continuing operations		$ (62,689)	$ 186,511	$ 145,531
Net income from discontinued operations		294,866	13,248	9,134
Net income		232,177	199,759	154,665
Adjustments to reconcile net income to net cash provided by operating activities
Provision for (release of) allowance for loan losses		20,052	17,925	(9,686)
Depreciation and amortization		12,295	11,985	11,900
Amortization (accretion) of of deferred loan fees and premiums, net		6,445	(1,441)	(27,991)
Deferred income tax (benefit) expense		(18,267)	5,262	(5,663)
Amortization of investment security premiums and discounts, net		6,281	18,274	16,713
Right-of-use asset amortization		11,348	11,432	10,982
Share-based compensation		16,047	10,507	0
Increase in cash surrender value of bank-owned life insurance		(3,912)	(3,699)	(2,348)
Loss (gain) on life insurance benefits		0	663	(1,813)
Loss (gain) on sales of securities available for sale, net		333,170	3,157	(1,166)
(Gain) loss on sales of bank premises and equipment, net		0	(1,412)	4,715
Loss on lease termination/modification, net		395	593	2,582
Accretion of gains from terminated interest rate swaps		(46)	(10,193)	(31,234)
Employee Stock Ownership Plan expense		7,129	9,923	9,408
Loss on sales of commercial loans		2,738	0	0
Proceeds from sale of commercial loan transferred to held for sale		22,126	0	0
Other		25	17	(106)
Change in:
Loans held for sale		3,403	(3,354)	(47)
Prepaid pension expense		4,260	4,338	1,130
Other assets		(14,394)	5,431	62,380
Other liabilities		39,035	(52,800)	(16,132)
Net cash provided by operating activities - continuing operations		385,441	213,119	169,155
Net cash (used in) provided by operating activities - discontinued operations		(123,749)	16,823	5,335
Net cash provided by operating activities		261,692	229,942	174,490
Investing activities
Proceeds from sales of securities available for sale		1,899,724	431,193	23,798
Proceeds from maturities and principal paydowns of securities available for sale		423,885	1,049,522	939,575
Purchases of securities available for sale		0	(740,770)	(3,323,893)
Proceeds from maturities and principal paydowns of securities held to maturity		27,397	17,399	0
Purchases of securities held to maturity		0	(493,678)	0
Proceeds from sale of Federal Home Loan Bank stock		286,309	63,715	6,692
Purchases of Federal Home Loan Bank stock		(250,850)	(94,174)	(2,101)
Contributions to low income housing tax credit investments		(36,939)	(19,487)	(11,379)
Contributions to other equity investments		(720)	(788)	(2,519)
Distributions from other equity investments		362	1,170	337
Proceeds from life insurance policies		0	20,446	0
Net (increase) decrease in outstanding loans, excluding loan purchases and sales		(586,584)	(926,255)	380,807
Proceeds from sales of commercial loans held for investment		189,296	0	0
Purchases of loans		(31,980)	(380,234)	0
Acquisitions, net of cash and cash equivalents acquired		0	0	(9,085)
Purchased banking premises and equipment		(8,140)	(8,627)	(5,728)
Proceeds from sale of bank premises and equipment		0	17,313	21,981
Proceeds from sale of other real estate owned		0	0	125
Net cash provided by (used in) investing activities - continuing operations		1,911,760	(1,063,255)	(1,981,390)
Net cash provided by (used in) investing activities - discontinued operations		488,505	(13,400)	(4,354)
Net cash provided by (used in) investing activities		2,400,265	(1,076,655)	(1,985,744)
Financing activities
Net (decrease) increase in demand, savings, interest checking, and money market investment deposit accounts		(2,462,797)	(1,751,953)	1,155,868
Net increase (decrease) in time deposits		1,084,655	1,098,001	(58,144)
Net (decrease) increase in borrowed funds		(692,612)	706,550	2,580
Repayment of acquired subordinated debentures	[1]	0	0	(36,277)
Payments for repurchases of common stock		0	(201,618)	(23,224)
Dividends declared and paid to common shareholders		(66,671)	(65,886)	(51,564)
Net cash (used in) provided by financing activities - continuing operations		(2,137,425)	(214,906)	989,239
Net cash used in financing activities - discontinued operations		(961)	(668)	(263)
Net cash (used in) provided by financing activities		(2,138,386)	(215,574)	988,976
Net increase (decrease) in cash, cash equivalents, and restricted cash		523,571	(1,062,287)	(822,278)
Cash, cash equivalents, and restricted cash at beginning of period		169,505	1,231,792	2,054,070
Cash, cash equivalents, and restricted cash at end of period		693,076	169,505	1,231,792
Cash paid during the period for:
Interest paid on deposits and borrowings		231,765	35,241	5,354
Income taxes		65,921	41,751	43,299
Non-cash activities
Net increase in capital commitments relating to low income housing tax credit projects		102,001	55,233	28,291
Maturity of acquired securities sold under agreements to repurchase	[2]	0	0	274,982
Net decrease in operating lease right of use assets and operating lease liabilities relating to lease remeasurements		$ 3,881	$ 14,836	$ 0

[1] (1)The Company deposited funds into escrow prior to the Century acquisition date to pay the balance of subordinated debentures assumed in the Century acquisition which was considered to be a defeasance of the debt. Accordingly, Century recorded a payable to the Company in the amount of the escrow deposit and the Company recorded a receivable from Century in the same amount. The payable was reclassified to other assets upon acquisition and is reflected as such balance in the summary of net assets acquired. Subsequent to the closing of the acquisition and prior to December 31, 2021, the amounts placed in escrow were disbursed to the holders of the subordinated debentures resulting in a full pay-off of the outstanding balance of the debt.

[2] (2)Includes non-cash item representing maturity of acquired securities sold under agreements to repurchase which were converted to deposits upon maturity.