Comprehensive Income (Loss), Net of Tax - Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Before-Tax Amount
Other comprehensive income (loss)	$ 21,880	$ (67,180)	$ 1,563
Tax (Benefit) Expense
Other comprehensive income (loss)	(5,641)	17,178	(400)
Net-of-Tax Amount
Other comprehensive income (loss) before reclassifications	8,897	(50,364)	1,016
Prior Service Cost	(391)	0	0
Reclassification from AOCI, current period	7,342	362	147
Other Comprehensive Income (Loss)	16,239	(50,002)	1,163
Net Unrealized Securities Holding Gains (Losses) Arising During the Period
Before-Tax Amount
OCI, before reclassifications	14,070	(64,774)	(8,616)
Reclassification from AOCI, current period	9,097
Tax (Benefit) Expense
Other Comprehensive Income (Loss) before Reclassifications, Tax	(3,629)	16,547	2,203
Reclassification from AOCI, current period	(2,345)
Net-of-Tax Amount
Other comprehensive income (loss) before reclassifications	10,441	(48,227)	(6,413)
Reclassification from AOCI, current period	6,752	0	0
Other Comprehensive Income (Loss)	17,193	(48,227)	(6,413)
Net Unrealized Gains (Losses) on Cash Flow Swap
Before-Tax Amount
OCI, before reclassifications	(3,908)	3,467	1,249
Reclassification from AOCI, current period	750	204	(126)
Tax (Benefit) Expense
Other Comprehensive Income (Loss) before Reclassifications, Tax	1,008	(885)	(320)
Reclassification from AOCI, current period	(193)	(52)	32
Net-of-Tax Amount
Other comprehensive income (loss) before reclassifications	(2,900)	2,582	929
Reclassification from AOCI, current period	557	152	(94)
Other Comprehensive Income (Loss)	(2,343)	2,734	835
Net Actuarial Gain (Loss)
Before-Tax Amount
OCI, before reclassifications	2,354	(6,938)	8,733
Prior Service Cost	(526)
Reclassification from AOCI, current period	(162)	56	91
Tax (Benefit) Expense
Other Comprehensive Income (Loss) before Reclassifications, Tax	(607)	1,791	(2,233)
Prior Service Cost	135
Reclassification from AOCI, current period	43	(15)	(23)
Net-of-Tax Amount
Other comprehensive income (loss) before reclassifications	1,747	(5,147)	6,500
Prior Service Cost	(391)
Reclassification from AOCI, current period	(119)	41	68
Other Comprehensive Income (Loss)	1,628	(5,106)	6,568
Settlement Cost
Before-Tax Amount
Reclassification from AOCI, current period		577
Tax (Benefit) Expense
Reclassification from AOCI, current period		(149)
Net-of-Tax Amount
Reclassification from AOCI, current period		428
Amortization of Net Retirement Plan Prior Service Cost
Before-Tax Amount
Reclassification from AOCI, current period	205	228	232
Tax (Benefit) Expense
Reclassification from AOCI, current period	(53)	(59)	(59)
Net-of-Tax Amount
Other comprehensive income (loss) before reclassifications	(391)	428	0
Reclassification from AOCI, current period	152	169	173
Other Comprehensive Income (Loss)	$ (239)	$ 597	$ 173