Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Before Tax Amount
Income (loss) before tax amount		$ 20,936	$ 16,424	$ 47,017	$ 41,592
Net unrealized gains (losses) on available-for-sale investment securities, before tax amount
Net unrealized holding losses arising during the period		(3,182)	(15,336)	2,211	(35,705)
Provision for credit losses		105	417	397	763
Less: reclassification adjustment for net gains on sales realized in net income				0	(30)
Other comprehensive income (loss), securities, available-for-sale, adjustment, before tax		(3,077)	(14,919)	2,608	(34,972)
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		(5,481)	1,626	(4,175)	1,702
Less: reclassification adjustment for net losses (gains) realized in net income (1)	[1]	1,371	(686)	2,431	(618)
Total net unrealized (losses) gains on interest rate swaps used in cash flow hedges		(4,110)	940	(1,744)	1,084
Defined benefit pension plans, Before Tax Amount
Amortization of net actuarial loss included in net periodic pension costs	[2]	246	218	492	436
Total defined benefit pension plans		246	218	492	436
Other comprehensive income (loss), before tax amount		(6,941)	(13,761)	1,356	(33,452)
Total comprehensive income (loss), before tax amount		13,995	2,663	48,373	8,140
Tax Expense (Benefit)
Income tax expense		4,136	3,258	9,183	8,109
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		(668)	(3,220)	465	(7,498)
(Reversal of provision) provision for credit losses, tax		22	87	83	160
Less: reclassification adjustment for net gains on sales realized in net income				0	(6)
Total net unrealized losses on available-for-sale investment securities		(646)	(3,133)	548	(7,344)
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		(1,151)	342	(877)	358
Less: reclassification adjustment for net losses (gains) realized in net income (1)	[1]	288	(144)	511	(130)
Total net unrealized (losses) gains on interest rate swaps used in cash flow hedges		(863)	198	(366)	228
Defined benefit pension plans, tax expense (benefit)
Amortization of net actuarial loss included in net periodic pension costs	[2]	52	46	104	92
Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, tax		52	46	104	92
Other comprehensive income (loss), tax expense (benefit)		(1,457)	(2,889)	286	(7,024)
Total comprehensive income (loss), tax expense (benefit)		2,679	369	9,469	1,085
Net of Tax Amount
Net income		16,800	13,166	37,834	33,483
Net unrealized gains (losses) on available-for-sale investment securities, net of tax amount
Net unrealized holding losses arising during the period		(2,514)	(12,116)	1,746	(28,207)
Provision for credit losses		(83)	(330)	(314)	(603)
Less: reclassification adjustment for net gains on sales realized in net income				0	(24)
Other comprehensive income (loss), securities, available-for-sale, adjustment, after tax		(2,431)	(11,786)	2,060	(27,628)
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		(4,330)	1,284	(3,298)	1,344
Less: reclassification adjustment for net losses (gains) realized in net income (1)	[1]	1,083	(542)	1,920	(488)
Total net unrealized (losses) gains on interest rate swaps used in cash flow hedges		(3,247)	742	(1,378)	856
Defined benefit pension plans, net of tax amount
Amortization of net actuarial loss included in net periodic pension costs	[2]	194	172	388	344
Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, after tax		194	172	388	344
Other comprehensive income (loss), net of tax amount		(5,484)	(10,872)	1,070	(26,428)
Total comprehensive income (loss), net of tax amount		$ 11,316	$ 2,294	$ 38,904	$ 7,055

[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.