Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Before Tax Amount
Income (loss) before tax amount		$ 25,986	$ 26,173	$ 67,578	$ 92,340
Net unrealized gains (losses) on available-for-sale investment securities, before tax amount
Net unrealized holding losses arising during the period		(18,093)	(1,378)	(53,798)	1,604
(Reversal of provision) provision for credit losses		(393)	330	370	(54)
Less: reclassification adjustment for net gains on sales realized in net income	[1]	0	(21)	(30)	(140)
Other comprehensive income (loss), securities, available-for-sale, adjustment, before tax		(18,486)	(1,069)	(53,458)	1,410
Net unrealized gains (losses) on interest rate swaps used in cash flow hedges, before tax amount
Net unrealized holding losses arising during the period		(9,418)	(7)	(7,716)	(5)
Less: reclassification adjustment for net (gains) losses realized in net income (2)	[2]	(422)	77	(1,040)	229
Total net unrealized (losses) gains on interest rate swaps used in cash flow hedges		(9,840)	70	(8,756)	224
Defined benefit pension plans, Before Tax Amount
Amortization of net actuarial loss included in net periodic pension costs	[3]	219	329	655	987
Total defined benefit pension plans		219	329	655	987
Other comprehensive income (loss), before tax amount		(28,107)	(670)	(61,559)	2,621
Total comprehensive income (loss), before tax amount		(2,121)	25,503	6,019	94,961
Tax Expense (Benefit)
Income tax expense		5,185	5,262	13,294	17,951
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		(3,800)	(292)	(11,298)	336
(Reversal of provision) provision for credit losses, tax		(82)	70	78	(11)
Less: reclassification adjustment for net gains on sales realized in net income	[1]	0	(4)	(6)	(29)
Total net unrealized losses on available-for-sale investment securities		(3,882)	(226)	(11,226)	296
Net unrealized gains (losses) on interest rate swaps used in cash flow hedges, tax expense (benefit)
Net unrealized holding losses arising during the period		(1,978)	(1)	(1,621)	(1)
Less: reclassification adjustment for net (gains) losses realized in net income (2)	[2]	(89)	16	(218)	48
Total net unrealized (losses) gains on interest rate swaps used in cash flow hedges		(2,067)	15	(1,839)	47
Defined benefit pension plans, tax expense (benefit)
Amortization of net actuarial loss included in net periodic pension costs	[3]	46	69	138	207
Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, tax		46	69	138	207
Other comprehensive income (loss), tax expense (benefit)		(5,903)	(142)	(12,927)	550
Total comprehensive income (loss), tax expense (benefit)		(718)	5,120	367	18,501
Net of Tax Amount
Net income		20,801	20,911	54,284	74,389
Net unrealized gains (losses) on available-for-sale investment securities, net of tax amount
Net unrealized holding losses arising during the period		(14,293)	(1,086)	(42,500)	1,268
(Reversal of provision) provision for credit losses		311	(260)	(292)	43
Less: reclassification adjustment for net gains on sales realized in net income	[1]	0	(17)	(24)	(111)
Other comprehensive income (loss), securities, available-for-sale, adjustment, after tax		(14,604)	(843)	(42,232)	1,114
Net unrealized gains (losses) on interest rate swaps used in cash flow hedges, net of tax amount
Net unrealized holding losses arising during the period		(7,440)	(6)	(6,095)	(4)
Less: reclassification adjustment for net (gains) losses realized in net income (2)	[2]	(333)	61	(822)	181
Total net unrealized (losses) gains on interest rate swaps used in cash flow hedges		(7,773)	55	(6,917)	177
Defined benefit pension plans, net of tax amount
Amortization of net actuarial loss included in net periodic pension costs	[3]	173	260	517	780
Other comprehensive (income) loss, defined benefit plan, after reclassification adjustment, after tax		173	260	517	780
Other comprehensive income (loss), net of tax amount		(22,204)	(528)	(48,632)	2,071
Total comprehensive income (loss), net of tax amount		$ (1,403)	$ 20,383	$ 5,652	$ 76,460

[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.