RELATED PARTY BALANCES AND TRANSACTIONS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Related Party Transaction [Abstract]
Accounts payable	$ 3,806		$ 3,806		$ 1,215
Purchase of materials	4,628	$ 2,852	10,665	$ 7,848
Service fee charged by	36	0	226	0
Ninebell Co., Ltd [Member]
Related Party Transaction [Abstract]
Prepaid expenses	2,272		2,272		348
Accounts payable	3,197		3,197		727
Purchase of materials	4,029	2,591	9,552	7,395
Service fee charged by	22	0	22	0
Shengyi Semiconductor Technology Co., Ltd [Member]
Related Party Transaction [Abstract]
Accounts payable	609		609		$ 488
Purchase of materials	599	261	1,113	453
Service fee charged by	$ 14	$ 0	$ 204	$ 0