Commitments and Contingencies - Additional Information (Details)			1 Months Ended			12 Months Ended
	Dec. 21, 2020	Dec. 29, 2016 USD ($)	Sep. 30, 2020 USD ($)	Jan. 31, 2020 ft²	Nov. 30, 2018	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) ft²	Sep. 30, 2021 USD ($)	Feb. 01, 2020 ft²
Lessee Lease Description [Line Items]
Restricted cash						$ 40,000	$ 909,000
Operating lease, liability						536,000
Right-of-use lease assets						536,000	15,491,000
Operating lease, cash payments						3,000,000.0	3,800,000
Lease expense						$ 2,300,000	2,900,000
Operating lease weighted-average remaining lease term						2 years 9 months 18 days
Operating lease weighted-average discount rate						4.00%
Tetraphase Pharmaceuticals, Inc.
Lessee Lease Description [Line Items]
Restricted cash						$ 0
Standby Letters of Credit | Tetraphase Pharmaceuticals, Inc.
Lessee Lease Description [Line Items]
Security deposit						200,000
Waltham Lease
Lessee Lease Description [Line Items]
Expiration date	Nov. 30, 2023
Operating lease, liability						0
Right-of-use lease assets						$ 0
San Diego Lease
Lessee Lease Description [Line Items]
Term of lease contract		10 years
Renewal term of lease contract		5 years
Lessee, Operating Lease, Existence of Option to Extend [true false]		true
Operating lease option to extend						The Company had an option to extend the San Diego Lease for an additional 5 years at the end of the Initial Lease Term
Lessee, Operating Lease, Existence of Option to Terminate [true false]						true
Lessee, option to terminate, description						On August 6, 2020, La Jolla received notice from the Landlord that the Landlord exercised its option to terminate the San Diego Lease effective August 31, 2020
Restricted cash						$ 0
Operating lease, liability			$ 0					$ 0
Lease cancellable written notice period			30 days
Payments of sublease			$ 64,000
Right-of-use lease assets			$ 0
Loss on termination of lease						$ 13,000,000.0
San Diego Lease | Standby Letters of Credit
Lessee Lease Description [Line Items]
Security deposit		$ 900,000					$ 600,000
Tetraphase Agreement with Watertown Lease
Lessee Lease Description [Line Items]
Lessee, Operating Lease, Existence of Option to Extend [true false]					true
Operating lease option to extend						In November 2018, Tetraphase entered into an Eighth Amendment to the Watertown Lease to extend the term of the lease through November 30, 2022 (the “Lease Term”)
Premises space leased | ft²							37,438		21,539
Decrease in space of premises lease | ft²				15,899
Operating lease, cash payments						$ 500,000
Estimated remaining future lease payments						$ 2,100,000