Investments (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Marketable Securities [Line Items]
Amortized Cost	$ 69,212,000		$ 69,212,000		$ 60,909,000
Gains	0		0		0
Losses	(856,000)		(856,000)		(154,000)
Credit Losses	0		0		0
Estimated Fair Value	68,356,000		$ 68,356,000		$ 60,755,000
Remaining contractual maturity period			3 years		3 years
Impairments of assets	0	$ 0	$ 0	$ 0
Short-term investments
Marketable Securities [Line Items]
Estimated Fair Value	44,638,000		44,638,000		$ 35,068,000
Long-term investments
Marketable Securities [Line Items]
Estimated Fair Value	23,718,000		23,718,000		25,687,000
Commercial paper
Marketable Securities [Line Items]
Amortized Cost	15,784,000		15,784,000		10,243,000
Gains	0		0		0
Losses	(76,000)		(76,000)		(12,000)
Credit Losses	0		0		0
Estimated Fair Value	15,708,000		15,708,000		10,231,000
Corporate notes
Marketable Securities [Line Items]
Amortized Cost	53,428,000		53,428,000		50,666,000
Gains	0		0		0
Losses	(780,000)		(780,000)		(142,000)
Credit Losses	0		0		0
Estimated Fair Value	$ 52,648,000		$ 52,648,000		$ 50,524,000