LEASES - Additional Information (Detail) $ in Thousands		12 Months Ended
	May 01, 2018	Dec. 31, 2020 USD ($) renewal_option	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Operating Leased Assets [Line Items]
Security deposit		$ 40,725	$ 14,825
Lease expense		50,700	52,400	$ 40,600
Net cash paid included in operating activities in cash flow		$ 38,000	$ 33,700
Operating lease, weighted average remaining lease term		12 years	13 years
Operating lease, weighted-average discount rate		8.00%	8.00%
BMR-675 West Kendall Lease
Operating Leased Assets [Line Items]
Lease term	15 years
Number of lease extension options | renewal_option		2
Operating lease renewal options period		5 years
Security deposit		$ 14,800
Third Street Lease
Operating Leased Assets [Line Items]
Number of lease extension options | renewal_option		2
Operating lease renewal options period		5 years
101 Main Street Leases
Operating Leased Assets [Line Items]
Number of lease extension options | renewal_option		1
Operating lease renewal options period		5 years