Accumulated Other Comprehensive Income (Loss) (Tables)

12 Months Ended

Dec. 31, 2023

Equity [Abstract]

Schedule of AOCI

The following table summarizes the changes within each classification of AOCI, net of tax:

(dollars in thousands)	Unrealized Gains and Losses on Available- for-Sale Debt Securities		Unrealized Gains and Losses on Held-to- Maturity Securities		Gains and Losses on Hedges		Defined Benefit Pension Plans		Total
Year Ended December 31, 2023
Balance at beginning of period	$	(642,346)	$	(112,664)	$	(31,549)	$	137	$	(786,422)
Other comprehensive income (loss) before       reclassifications	(14,817)		1,325		51,871		—		38,379
Amounts reclassified from AOCI to income (1)	4,645		15,867		(11,141)		(137)		9,234
Balance at end of period	$	(652,518)	$	(95,472)	$	9,181	$	—	$	(738,809)
Year Ended December 31, 2022
Balance at beginning of period	$	(2,950)	$	—	$	543	$	32	$	(2,375)
Other comprehensive income (loss) before       reclassifications	(639,463)		(125,229)		(34,043)		—		(798,735)
Amounts reclassified from AOCI to income (1)	67		12,565		1,951		105		14,688
Balance at end of period	$	(642,346)	$	(112,664)	$	(31,549)	$	137	$	(786,422)
Year Ended December 31, 2021
Balance at beginning of period	$	145,335	$	—	$	2,584	$	(148)	$	147,771
Other comprehensive income (loss) before       reclassifications	(144,948)		—		1,433		—		(143,515)
Amounts reclassified from AOCI to income (1)	(3,337)		—		(3,474)		180		(6,631)
Balance at end of period	$	(2,950)	$	—	$	543	$	32	$	(2,375)

(1)See table below for details about reclassifications to income.

Schedule of Reclassifications out of AOCI

The following table summarizes the significant amounts reclassified out of each component of AOCI:

	Years Ended December 31,
(dollars in thousands)	2023		2022		2021
Details about AOCI Components	Amount Reclassified from AOCI						Affected Line Item in the Statement of Income
Unrealized gains and losses on    available-for-sale debt securities	$	(6,265)	$	(88)	$	4,327	Debt securities gains (losses), net
	1,620		21		(990)		Income tax (expense) benefit
	$	(4,645)	$	(67)	$	3,337	Net income
Amortization of unrealized losses on    held-to-maturity securities transferred    from available-for-sale	$	(21,239)	$	(16,612)	$	—	Interest income (expense)
	5,372		4,047		—		Income tax (expense) benefit
	$	(15,867)	$	(12,565)	$	—	Net income
Gains and losses on hedges    Interest rate contracts	$	15,067	$	(2,587)	$	4,605	Interest income (expense)
	(3,926)		636		(1,131)		Income tax (expense) benefit
	$	11,141	$	(1,951)	$	3,474	Net income
Amortization of defined benefit    pension items
Actuarial gains (losses)	$	182	$	(139)	$	(239)	Salaries and employee benefits
	(45)		34		59		Income tax (expense) benefit
	$	137	$	(105)	$	(180)	Net income
Total reclassifications for the period	$	(9,234)	$	(14,688)	$	6,631	Net income