Accumulated Other Comprehensive Income (''AOCI'') - Changes in AOCI by Component (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Changes in AOCI by Component
Balance at the beginning of the period, net of taxes		$ (10,996)			$ (10,996)
Net current period other comprehensive income (loss), net of taxes	$ (1,864)	(3,058)	$ (264)	$ (551)	(4,922)	$ (815)
Balance at the end of the period, net of taxes	(15,918)				(15,918)
Accumulated Other Comprehensive Income / (Loss)
Changes in AOCI by Component
Balance at the beginning of the period, net of taxes	(14,054)	(10,996)	(11,268)	(10,717)	(10,996)	(10,717)
Other comprehensive loss before reclassification, net of taxes	(1,937)		(403)		(5,068)	(1,058)
Amounts reclassified from other comprehensive income (loss), net of taxes	73		139		146	243
Net current period other comprehensive income (loss), net of taxes	(1,864)	(3,058)	(264)	(551)	(4,922)	(815)
Balance at the end of the period, net of taxes	(15,918)	(14,054)	(11,532)	(11,268)	(15,918)	(11,532)
Unrealized Gains (Losses) on Available-for-Sale Securities and I/O Strips
Changes in AOCI by Component
Balance at the beginning of the period, net of taxes	(975)	2,153	3,327	3,929	2,153	3,929
Other comprehensive loss before reclassification, net of taxes	(1,934)		(454)		(5,062)	(1,056)
Net current period other comprehensive income (loss), net of taxes	(1,934)		(454)		(5,062)	(1,056)
Balance at the end of the period, net of taxes	(2,909)	(975)	2,873	3,327	(2,909)	2,873
Amortization of unrealized gain on securities available-for-sale that were reclassified to securities held-to-maturity
Changes in AOCI by Component
Balance at the beginning of the period, net of taxes			252	261		261
Amounts reclassified from other comprehensive income (loss), net of taxes			(9)			(18)
Net current period other comprehensive income (loss), net of taxes			(9)			(18)
Balance at the end of the period, net of taxes			243	252		243
Defined Benefit Pension Plan Items
Changes in AOCI by Component
Balance at the beginning of the period, net of taxes	(13,079)	(13,149)	(14,847)	(14,907)	(13,149)	(14,907)
Other comprehensive loss before reclassification, net of taxes	(3)		51		(6)	(2)
Amounts reclassified from other comprehensive income (loss), net of taxes	73		148		146	261
Net current period other comprehensive income (loss), net of taxes	70		199		140	259
Balance at the end of the period, net of taxes	$ (13,009)	$ (13,079)	$ (14,648)	$ (14,847)	$ (13,009)	$ (14,648)