Quarterly report pursuant to Section 13 or 15(d)

Restricted Cash Equivalents and Investments (Schedule of Estimated Fair Value of Available-for-Sale Securities) (Details)

v3.22.1
Restricted Cash Equivalents and Investments (Schedule of Estimated Fair Value of Available-for-Sale Securities) (Details)
$ in Thousands
Mar. 31, 2022
USD ($)
Schedule of Available-for-sale Securities [Line Items]  
Amortized Cost $ 3,577
Estimated Market Value 3,521
Investments [Member]  
Schedule of Available-for-sale Securities [Line Items]  
Amortized Cost, Due within one year 797
Amortized Cost, Due after one year through five years 2,098
Amortized Cost 2,895
Estimated Market Value, Due within one year 787
Estimated Market Value, Due after one year through five years 2,052
Estimated Market Value $ 2,839