RIGHT-OF-USE ASSETS UNDER OPERATING LEASES, NET (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Leases [Abstract]
Right-of-use assets under operating leases	$ 26,554		$ 26,554		$ 31,932
Less: Accumulated amortization	(13,370)		(13,370)		(13,719)
Total	13,184		13,184		$ 18,213
Amortization of right-of-use assets under operating leases	$ 1,800	$ 2,600	$ 6,340	$ 8,107