Cash and Cash Equivalents and Investments (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Cash and Cash Equivalents
Realized Investment Gains (Losses)	$ 0
Available-for-sale Securities, Amortized Cost Basis	15,125
Available-for-sale Securities, Gross Unrealized Gain Accumulated in Investments	0
Available-for-sale Securities, Gross Unrealized Losses	(8)
Available-for-sale Securities, Current	15,117
Cash
Cash and Cash Equivalents
Available-for-sale Securities, Amortized Cost Basis	64,066	$ 126,263
Available-for-sale Securities, Gross Unrealized Gain Accumulated in Investments	0	0
Available-for-sale Securities, Gross Unrealized Losses	1	0
Available-for-sale Securities, Current	64,065	126,263
US Treasury Securities
Cash and Cash Equivalents
Available-for-sale Securities, Amortized Cost Basis	7,562
Available-for-sale Securities, Gross Unrealized Gain Accumulated in Investments	0
Available-for-sale Securities, Gross Unrealized Losses	(1)
Available-for-sale Securities, Current	7,561	26,012
Short-term Investments
Cash and Cash Equivalents
Available-for-sale Securities, Amortized Cost Basis	22,687	26,018
Available-for-sale Securities, Gross Unrealized Gain Accumulated in Investments	0	5
Available-for-sale Securities, Gross Unrealized Losses	(9)	(11)
Available-for-sale Securities, Current	22,678	26,012
Cash and Cash Equivalents and Investments
Cash and Cash Equivalents
Available-for-sale Securities, Amortized Cost Basis	86,753	152,281
Available-for-sale Securities, Gross Unrealized Gain Accumulated in Investments	0	5
Available-for-sale Securities, Gross Unrealized Losses	(10)	(11)
Available-for-sale Securities, Current	$ 86,743	$ 152,275

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

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Amount of realized gain (loss) on investment.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04.3(a))
-URI http://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263

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