Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Before Tax Amount
Income (loss) before tax amount		$ 26,081	$ 25,168
Net unrealized gains (losses) on available-for-sale investment securities, before tax amount
Net unrealized holding gains (losses) arising during the period		5,393	(20,369)
Provision for credit losses		292	346
Less: reclassification adjustment for net gains on sales realized in net income	[1]	0	(30)
Other comprehensive income (loss), securities, available-for-sale, adjustment, before tax		5,685	(20,053)
Net unrealized gains (losses) on interest rate swaps used in cash flow hedges, before tax amount
Net unrealized holding gains arising during the period		1,306	76
Less: reclassification adjustment for net losses realized in net income (2)	[2]	1,060	68
Total net unrealized gains on interest rate swaps used in cash flow hedges		2,366	144
Defined benefit pension plans, Before Tax Amount
Amortization of net actuarial loss included in net periodic pension costs	[3]	246	218
Total defined benefit pension plans		246	218
Other comprehensive income (loss), before tax amount		8,297	(19,691)
Total comprehensive income (loss), before tax amount		34,378	5,477
Tax Expense (Benefit)
Income tax expense		5,047	4,851
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		1,133	(4,278)
(Reversal of provision) provision for credit losses, tax		61	73
Less: reclassification adjustment for net gains on sales realized in net income	[1]	0	(6)
Total net unrealized gains (losses) on available-for-sale investment securities		1,194	(4,211)
Net unrealized gains (losses) on interest rate swaps used in cash flow hedges, tax expense (benefit)
Net unrealized holding gains arising during the period		274	16
Less: reclassification adjustment for net losses realized in net income (2)	[2]	223	14
Total net unrealized gains on interest rate swaps used in cash flow hedges		497	30
Defined benefit pension plans, tax expense (benefit)
Amortization of net actuarial loss included in net periodic pension costs	[3]	52	46
Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, tax		52	46
Other comprehensive income (loss), tax expense (benefit)		1,743	(4,135)
Total comprehensive income (loss), tax expense (benefit)		6,790	716
Net of Tax Amount
Net income		21,034	20,317
Net unrealized gains (losses) on available-for-sale investment securities, net of tax amount
Net unrealized holding gains (losses) arising during the period		4,260	(16,091)
Provision for credit losses		(231)	(273)
Less: reclassification adjustment for net gains on sales realized in net income	[1]	0	(24)
Other comprehensive income (loss), securities, available-for-sale, adjustment, after tax		4,491	(15,842)
Net unrealized gains (losses) on interest rate swaps used in cash flow hedges, net of tax amount
Net unrealized holding gains arising during the period		1,032	60
Less: reclassification adjustment for net losses realized in net income (2)	[2]	837	54
Total net unrealized gains on interest rate swaps used in cash flow hedges		1,869	114
Defined benefit pension plans, net of tax amount
Amortization of net actuarial loss included in net periodic pension costs	[3]	194	172
Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, after tax		194	172
Other comprehensive income (loss), net of tax amount		6,554	(15,556)
Total comprehensive income (loss), net of tax amount		$ 27,588	$ 4,761

[1] (1) Included in net gain on sales of investment securities on the condensed consolidated statements of income (before tax amount).

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

[3] (3) 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.