Subsequent Events	9 Months Ended
Sep. 30, 2021
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	12. SUBSEQUENT EVENTS In November 2021, the Company entered into an amendment of its December 2017 lease agreement (the “Lease Amendment”) for its corporate headquarters in Bedford, Massachusetts. The Lease Amendment increases the space under lease by approximately 23,011 square feet (the "Expansion Premises") and extends the expiration date of the existing premises under the lease from February 2027 to June 2030. The term with respect to the Expansion Premises commences on the earlier of (i) the date of the Substantial Completion of the Tenant’s Work (as both terms are defined in the Lease Amendment), (ii) the Company’s occupancy of any portion of the Expansion Premises, and (iii) May 1, 2022, and continues for a period of ten years and five months. The term of the Expansion Premises and the existing premises are not coterminous. Annual base rent for the existing premise under the Lease Amendment is approximately $4.2 million beginning on March 1, 2027, and increases by three percent annually; annual base rent for the Expansion Premises is approximately $1.4 million per year and increases by three percent annually. The Lease Amendment allows for a tenant improvement allowance not to exceed $5.3 million.

Subsequent Events

9 Months Ended

Sep. 30, 2021

12. SUBSEQUENT EVENTS

In November 2021, the Company entered into an amendment of its December 2017 lease agreement (the “Lease Amendment”) for its corporate headquarters in Bedford, Massachusetts. The Lease Amendment increases the space under lease by approximately 23,011 square feet (the "Expansion Premises") and extends the expiration date of the existing premises under the lease from February 2027 to June 2030. The term with respect to the Expansion Premises commences on the earlier of (i) the date of the Substantial Completion of the Tenant’s Work (as both terms are defined in the Lease Amendment), (ii) the Company’s occupancy of any portion of the Expansion Premises, and (iii) May 1, 2022, and continues for a period of ten years and five months. The term of the Expansion Premises and the existing premises are not coterminous. Annual base rent for the existing premise under the Lease Amendment is approximately $4.2 million beginning on March 1, 2027, and increases by three percent annually; annual base rent for the Expansion Premises is approximately $1.4 million per year and increases by three percent annually. The Lease Amendment allows for a tenant improvement allowance not to exceed $5.3 million.