Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 1,181	$ 6,185
Other comprehensive income (loss), before tax:
Accumulated postretirement benefit obligation adjustment	141	219
Net unrealized gains (losses) on investments arising during the period	233	(2,764)
Reclassification adjustment for write-down of securities included in net income	82	0
Other comprehensive income (loss), before income tax	456	(2,545)
Income tax expense related to postretirement health benefits	30	46
Income tax expense (benefit) related to net unrealized gains (losses) on investments arising during the period	47	(583)
Income tax expense related to reclassification adjustment for write-down of securities included in net income	19	0
Net income tax expense (benefit) on other comprehensive income (loss)	96	(537)
Other comprehensive income (loss)	360	(2,008)
Comprehensive Income	$ 1,541	$ 4,177