Restricted cash (Tables)

12 Months Ended

Dec. 31, 2020

Other Assets, Noncurrent [Abstract]

Schedule of collateralized bank account of financial institution

As of both December 31, 2020 and 2019, the Company maintained letters of credit of $54.5 million, which are collateralized with bank accounts at financial institutions in accordance with the agreements. Total restricted cash as of December 31, 2020 and 2019 consisted of the following (in thousands):

	As of December 31,
	2020		2019
60 Binney Street lease	$	13,763	$	13,763
50 Binney Street sublease	40,072		40,072
Other	2,188		660
Total restricted cash	$	56,023	$	54,495