Fair Value Measurements and Available for Sale Investments - Schedule of Unrealized Loss and Fair Values in a Loss Position (Details) - USD ($)	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	$ 8,259,000		$ 46,713,000
Less than 12 Months, Gross Unrealized Losses	(6,000)		(5,000)
12 Months or Greater, Fair Value	0		2,399,000
12 Months or Greater, Gross Unrealized Losses	0		0
Fair Value	8,259,000		49,112,000
Gross Unrealized Losses	(6,000)		(5,000)
Unrealized losses on available-for-sale	0	$ 0
Allowance for credit losses	0	$ 0
Agency securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	4,997,000		4,999,000
Less than 12 Months, Gross Unrealized Losses	(6,000)		(1,000)
12 Months or Greater, Fair Value	0		0
12 Months or Greater, Gross Unrealized Losses	0		0
Fair Value	4,997,000		4,999,000
Gross Unrealized Losses	(6,000)		(1,000)
Commercial and corporate obligations
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value	3,262,000		6,503,000
Less than 12 Months, Gross Unrealized Losses	0		(1,000)
12 Months or Greater, Fair Value	0		2,399,000
12 Months or Greater, Gross Unrealized Losses	0		0
Fair Value	3,262,000		8,902,000
Gross Unrealized Losses	$ 0		(1,000)
US Treasury Securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 Months, Fair Value			35,211,000
Less than 12 Months, Gross Unrealized Losses			(3,000)
12 Months or Greater, Fair Value			0
12 Months or Greater, Gross Unrealized Losses			0
Fair Value			35,211,000
Gross Unrealized Losses			$ (3,000)

Amount of unrealized loss on 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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Amount of allowance for credit loss on 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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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss.

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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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