Consolidated Statements Of Cash Flows (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Cash Flows [Abstract]
Deferred tax benefit (provision) related to unrealized loss (gain) on investments	$ 583	$ 163
Adjustments to postretirement benefits obligation, net of deferred tax benefit	$ (46)	$ 0