Cash Equivalents And Restricted Cash And Securities (Tables)	12 Months Ended
	Dec. 31, 2021
Cash Equivalents And Restricted Cash And Securities [Abstract]
Summary Of Cash Equivalents And Restricted Securities	Unrealized Estimated Holding MarketDecember 31, 2021Cost Basis Gains ValueCash equivalents: Money market funds$ 10,015 -- $ 10,015Total assets$ 10,015 $ -- $ 10,015 Unrealized Estimated Holding MarketDecember 31, 2020Cost Basis Gains ValueCash equivalents: Money market funds$ 11,484 -- $ 11,484Restricted securities: Money market funds 546 -- 546Total assets$ 12,030 $ -- $ 12,030