Marketable Securities - Maturities of Available-for-sale Securities (Details) $ in Thousands	Dec. 31, 2021 USD ($)
Marketable Securities
Due within one year, amortized cost	$ 1,785
Due after one year through five years, amortized cost	1,222
Total available-for-sale securities, amortized cost	3,007
Due within one year, estimated fair value	1,791
Due after one year through five years, estimated fair value	1,219
Total available-for-sale securities, estimated fair value	$ 3,010

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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