Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023
Before Tax Amount
Income (loss) before tax amount		$ 25,556	$ 26,081
Net unrealized gains (losses) on available-for-sale investment securities, before tax amount
Net unrealized holding (losses) gains arising during the period		(2,989)	5,393
Provision for credit losses		86	292
Other comprehensive income (loss), securities, available-for-sale, adjustment, before tax		(2,903)	5,685
Net unrealized gains (losses) on interest rate swaps used in cash flow hedges, before tax amount
Net unrealized holding (losses) gains arising during the period		(4,013)	1,306
Less: reclassification adjustment for net losses realized in net income	[1]	1,586	1,060
Total net unrealized (losses) gains on interest rate swaps used in cash flow hedges		(2,427)	2,366
Defined benefit pension plans, Before Tax Amount
Amortization of net actuarial loss included in net periodic pension costs	[2]	147	246
Total defined benefit pension plans		147	246
Other comprehensive income (loss), before tax amount		(5,183)	8,297
Total comprehensive income (loss), before tax amount		20,373	34,378
Tax Expense (Benefit)
Income tax expense		5,251	5,047
Net unrealized gains (losses) on available-for-sale investment securities, tax expense (benefit)
Other comprehensive income (loss), securities, available-for-sale, unrealized holding gain (loss) arising during period, tax		(628)	1,133
(Reversal of provision) provision for credit losses, tax		18	61
Total net unrealized (losses) gains on available-for-sale investment securities		(610)	1,194
Net unrealized gains (losses) on interest rate swaps used in cash flow hedges, tax expense (benefit)
Net unrealized holding (losses) gains arising during the period		(843)	274
Less: reclassification adjustment for net losses realized in net income	[1]	333	223
Total net unrealized (losses) gains on interest rate swaps used in cash flow hedges		(510)	497
Defined benefit pension plans, tax expense (benefit)
Amortization of net actuarial loss included in net periodic pension costs	[2]	31	52
Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, tax		31	52
Other comprehensive income (loss), tax expense (benefit)		(1,089)	1,743
Total comprehensive income (loss), tax expense (benefit)		4,162	6,790
Net of Tax Amount
Net income		20,305	21,034
Net unrealized gains (losses) on available-for-sale investment securities, net of tax amount
Net unrealized holding (losses) gains arising during the period		(2,361)	4,260
Provision for credit losses		(68)	(231)
Other comprehensive income (loss), securities, available-for-sale, adjustment, after tax		(2,293)	4,491
Net unrealized gains (losses) on interest rate swaps used in cash flow hedges, net of tax amount
Net unrealized holding (losses) gains arising during the period		(3,170)	1,032
Less: reclassification adjustment for net losses realized in net income	[1]	1,253	837
Total net unrealized (losses) gains on interest rate swaps used in cash flow hedges		(1,917)	1,869
Defined benefit pension plans, net of tax amount
Amortization of net actuarial loss included in net periodic pension costs	[2]	116	194
Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, after tax		116	194
Other comprehensive income (loss), net of tax amount		(4,094)	6,554
Total comprehensive income (loss), net of tax amount		$ 16,211	$ 27,588

[1] (1) Included in interest expense on demand deposits on the condensed consolidated statements of income (before tax amount).

[2] (2) These accumulated other comprehensive loss components are included in the computation of net periodic pension cost (before tax amount). See Note 8, "Retirement Plans and Other Postretirement Benefits" for additional details. Note: See accompanying notes to the unaudited condensed consolidated financial statements.