Leases - Additional Information (Details) $ in Thousands							3 Months Ended	6 Months Ended
	Apr. 22, 2021 USD ($)	Dec. 15, 2020 USD ($) ft²	Jun. 01, 2020 USD ($)	Apr. 13, 2020 USD ($) ft²	Oct. 15, 2019 USD ($) ft²	Mar. 12, 2019 USD ($) ft²	Jun. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Apr. 30, 2021 ft²	Dec. 31, 2020 USD ($)	Jan. 30, 2018 USD ($) ft²
Land Subject to Ground Leases | ft²						1,038			9,800
Operating Lease Monthly Rental Payment			$ 10			$ 2
Operating lease rental expenses							$ 5	$ 5
Lease obligation							5,656	5,656
Boston, MA
Security Deposit							100	$ 100		$ 100
Sublease term amendment								Aug. 31, 2021
Operating lease expiration month and year								2016-08
Lessee Operating Lease Monthly Rental Payment	$ 26
Houston, TX
Land Subject to Ground Leases | ft²		35,482			8,443
Operating Lease Area | ft²				5,584							210
Operating Leases Future Minimum Monthly Payment Due Through Year 2021		$ 37		$ 12	$ 17						$ 1
Annual Base Rent		3.00%		3.00%	3.00%
Lessee Operating Lease Monthly Rental Payment			$ 15
Lease obligation							$ 0	$ 0