Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Taxes

Schedule of provision for income taxes

	Year Ended December 31,
(Dollars in thousands)	2023		2022		2021
Current:
Federal	$	111,433	$	5,940	$	43,959
State		23,157		7,044		16,512
Total current tax expense		134,590		12,984		60,471
Deferred:
Federal		738		103,875		61,521
State		1,216		20,454		6,744
Total deferred tax expense		1,954		124,329		68,265
Provision for income taxes	$	136,544	$	137,313	$	128,736

Schedule of provision for income taxes and taxes computed by applying the federal statutory income tax rate to income before provision for income taxes

	Year Ended December 31,
(Dollars in thousands)	2023		2022		2021
Income taxes at federal statutory rate	$	132,479	$	133,006	$	126,899
Increase (reduction) of taxes resulting from:
State income taxes, net of federal tax benefit		19,123		21,491		18,372
Non-deductible merger expenses		—		415		—
Increase in cash surrender value of BOLI policies		(5,605)		(5,105)		(3,866)
Tax-exempt interest		(7,016)		(7,828)		(5,450)
Income tax credits		(14,253)		(13,667)		(11,759)
Non-deductible FDIC premiums		5,330		3,287		2,380
Non-deductible executive compensation		4,745		4,319		530
Other, net		1,741		1,395		1,630
	$	136,544	$	137,313	$	128,736

Schedule of components of the net deferred tax asset

	December 31,
(Dollars in thousands)	2023		2022
Allowance for credit losses	$	123,496	$	101,416
Share-based compensation		10,425		10,509
Pension plan and post-retirement benefits		371		1,157
Deferred compensation		14,039		14,583
Purchase accounting adjustments		1,439		1,484
Capitalized research and development costs		4,524		—
Accrued expenses		14,470		6,953
Other real estate owned		—		877
FDIC special assessment		6,168		—
Net operating loss and tax credit carryforwards		20,263		27,271
Nonaccrual Interest		1,773		566
Lease liability		26,076		27,675
Unrealized losses on investment securities available for sale		142,543		215,013
Other		2,201		1,277
Total deferred tax assets		367,788		408,781
Depreciation		10,439		22,442
Intangible assets		17,764		23,558
Net deferred loan costs		16,468		10,431
Right of use assets		24,161		25,848
Prepaid expense		809		836
Mark to market liabilities		92,505		110,122
Tax deductible goodwill		12,398		9,090
Mortgage servicing rights		20,863		21,371
Other real estate owned		192		—
Other		3,950		1,776
Total deferred tax liabilities		199,549		225,474
Net deferred tax assets before valuation allowance		168,239		183,307
Less, valuation allowance		(3,885)		(5,506)
Net deferred tax assets	$	164,354	$	177,801

Schedule of reconciliation of the beginning balance and ending amount of unrecognized tax benefits

	Year Ended December 31,
(Dollars in thousands)	2023
Balance at beginning of year	$	—
Increases related to prior year tax positions		12,352
Increases related to current year tax positions		693
Balance at end of year	$	13,045