CONCENTRATION OF RISK (Tables)

3 Months Ended

Mar. 31, 2022

Risks and Uncertainties [Abstract]

Revenues and Accounts Receivable From Our Largest Customers

Revenues and accounts receivable from the Company's largest customers were as follows (in thousands):

	% of Total Revenue for the  Three Months Ended March 31,		Accounts Receivable as of
Customer	2022	2021	March 31, 2022
A	40%	36%	$	8,216
B	27%	23%	$	42,813
C	15%	20%	$	20,622
D	7%	12%	$	6,870

Revenues by Geographic Area

Revenues by geographic area are as follows (in thousands):

	Three Months Ended March 31,
Country	2022		2021
South Korea	$	89,687	$	67,975
China		55,400		60,504
Japan		1,053		1,315
Other non-U.S. locations		300		825
Total non-U.S. locations		146,440		130,619
United States		4,030		3,381
Total revenue	$	150,470	$	134,000

Long-Lived Assets (Net) by Geographic Area

Long-lived assets (net), by geographic area are as follows (in thousands):

	March 31, 2022		December 31, 2021
United States	$	115,760	$	115,004
Other		16,119		13,828
Total long-lived assets	$	131,879	$	128,832