Cash and Investments in Marketable Securities - Additional Information (Details) - USD ($)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash and Investments in Marketable Securities [Line Items]
Sales of investments	$ 11,504,000	$ 41,700,000	$ 0
Accrued interest receivable	1,400,000	5,100,000
Gross unrealized gains	12,000	1,100,000
Gross unrealized losses	674,000	200,000
Letter of credit	$ 8,100,000	$ 8,100,000
Minimum
Cash and Investments in Marketable Securities [Line Items]
Long term investment maturity period	1 year
Maximum
Cash and Investments in Marketable Securities [Line Items]
Long term investment maturity period	2 years	2 years

Cash and Investments in Marketable Securities [Line Items]

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Long term investment maturity period.

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- Definition

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
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- Definition

Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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- Definition

Carrying amount as of the balance sheet date of current interest earned but not received. Also called accrued interest or accrued interest receivable. For classified balance sheets, represents the current amount receivable, that is amounts expected to be collected within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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- Definition

Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
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