Investments - Investments consists of available-for-sale securities (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Short Term Marketable Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 90,780	$ 89,594
Unrealized Loss	(431)	(36)
Estimated Fair Value	90,349	89,558
Long Term Marketable Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	11,874	25,006
Unrealized Loss	(173)	(87)
Estimated Fair Value	11,701	24,919
US Government Debt Securities [Member] | Short Term Marketable Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	21,518
Unrealized Loss	(164)
Estimated Fair Value	21,354
US Government Debt Securities [Member] | Long Term Marketable Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	0	3,996
Unrealized Loss	0	(17)
Estimated Fair Value	0	3,979
Corporate Bonds [Member] | Short Term Marketable Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	24,319	35,231
Unrealized Loss	(266)	(35)
Estimated Fair Value	24,053	35,196
Corporate Bonds [Member] | Long Term Marketable Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	11,874	21,010
Unrealized Loss	(173)	(70)
Estimated Fair Value	11,701	20,940
Commercial Paper [Member] | Short Term Marketable Securities [Member]
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	44,943	54,363
Unrealized Loss	(1)	(1)
Estimated Fair Value	$ 44,942	$ 54,362