Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020 USD ($) Segment shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($) shares
Summary Of Significant Accounting Policies [Line Items]
Realized gains and losses on marketable securities	$ 0	$ 0	$ 0
Other-than-temporary impairments on marketable securities	0	$ 0	$ 0
Transfers of assets measured on recurring basis out of Level 1 into Level 2	0
Transfers of assets measured on recurring basis out of Level 2 into Level 1	0
Transfers of liabilities measured on recurring basis out of Level 1 into Level 2	0
Transfers of liabilities measured on recurring basis out of Level 2 into Level 1	0
Transfers of financial instrument classified as liability into level 3	0
Transfers of financial instrument classified as liability out of level 3	0
Transfers of financial instrument classified as asset into level 3	0
Transfers of financial instrument classified as asset out of level 3	$ 0
Number of operating segment | Segment	1
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2019
Weighted-average shares/units subject to repurchase or forfeiture | shares	123,285	217,524	231,810
Minimum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of assets	3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives of assets	5 years