Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Summary of Differences in Taxes from Continuing Operations Computed at Statutory Rate

Following is a summary of the major items comprising the differences in taxes from continuing operations computed at the federal statutory rate and as recorded in the consolidated statement of income:


	Years Ended December 31,
(dollars in thousands)	2023			2022			2021
Provision at statutory rate of 21%	$	157,774		$	114,394		$	71,161
Tax-exempt income:
Tax-exempt interest	(18,582)			(14,588)			(11,066)
Section 291/265 interest disallowance	2,392			363			114
Company-owned life insurance income	(3,125)			(2,891)			(2,138)
Tax-exempt income	(19,315)			(17,116)			(13,090)
State income taxes	31,164			20,837			9,308
Tax credit investments - federal	(12,190)			(9,140)			(5,212)
Officer compensation limitation	4,685			5,903			564
Non-deductible FDIC premiums	7,912			3,805			438
Other, net	(720)			(2,237)			(1,845)
Income tax expense	$	169,310		$	116,446		$	61,324
Effective tax rate	22.5		%	21.4		%	18.1		%

Schedule of Provision for Income Taxes

The provision for income taxes consisted of the following components:


	Years Ended December 31,
(dollars in thousands)	2023		2022		2021
Current expense:
Federal	$	121,428	$	106,918	$	31,943
State	37,331		32,898		8,461
Deferred expense:
Federal	7,941		(16,216)		17,514
State	2,610		(7,154)		3,406
Deferred income tax expense	10,551		(23,370)		20,920
Income tax expense	$	169,310	$	116,446	$	61,324

Schedule of Significant Components of Net Deferred Tax Assets (Liabilities)

Significant components of net deferred tax assets (liabilities) were as follows:


	December 31,
(dollars in thousands)	2023		2022
Deferred Tax Assets
Unrealized losses on available-for-sale investment securities	$	217,018	$	202,101
Allowance for credit losses on loans, net of recapture	86,224		85,619
Operating lease liabilities	57,996		58,288
Unrealized losses on held-to-maturity investment securities	32,150		36,197
Acquired loans	32,011		40,723
Benefit plan accruals	31,679		38,038
Purchase accounting	22,473		20,063
Net operating loss carryforwards	21,004		25,135

FDIC deductible premiums	4,891		—

Unrealized losses on hedges	—		10,277

Other, net	4,860		4,962
Total deferred tax assets	510,306		521,403
Deferred Tax Liabilities

Operating lease right-of-use assets	(52,710)		(51,845)
Premises and equipment	(12,141)		(14,844)
Loan servicing rights	(9,188)		(9,636)
Prepaid expenses	(3,856)		(2,774)
Unrealized gains on hedges	(3,202)		—
Deferred loan origination fees	(2,361)		(3,566)


Other, net	(3,588)		(2,983)
Total deferred tax liabilities	(87,046)		(85,648)
Net deferred tax assets	$	423,260	$	435,755

Schedule of Unrecognized Tax Benefits

The following table presents the changes in the carrying amount of unrecognized tax benefits:


	Years Ended December 31,
(dollars in thousands)	2023		2022		2021
Balance at beginning of period	$	11,007	$	—	$	—
Additions for acquired uncertain tax positions	—		14,897		—
Additions based on tax positions related to prior years	60		—		—
Reductions for tax positions relating to prior years	—		(2,751)		—
Reductions due to statute of limitations expiring	(1,112)		(1,139)		—
Balance at end of period	$	9,955	$	11,007	$	—