CONCENTRATION OF RISK

9 Months Ended

Sep. 30, 2019

16.	CONCENTRATION OF RISK:

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

	% of Revenues for the Three Months Ended September 30,		% of Revenues for the Nine Months Ended September 30,		Accounts Receivable as of
Customer	2019	2018	2019	2018	September 30, 2019
A	56%	50%	45%	36%	$	21,615
B	21%	19%	24%	35%	$	9,820
C	12%	9%	17%	8%	$	19,609
D	1%	10%	5%	9%	$	444

Revenues from outside of North America represented approximately 97% and 96% of consolidated revenue for the three months ended September 30, 2019 and 2018, respectively, and 97% and 95% of consolidated revenue for the nine months ended September 30, 2019 and 2018, respectively. Revenues by geographic area are as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
Country	2019		2018		2019		2018
South Korea	$	70,042	$	53,883	$	190,303	$	126,789
China		23,205		17,037		98,955		34,368
Japan		1,137		3,076		3,802		4,637
Other non-U.S. locations		539		457		1,718		2,078
Total non-U.S. locations		94,923		74,453		294,778		167,872
United States		2,592		3,097		8,670		9,399
Total revenue	$	97,515	$	77,550	$	303,448	$	177,271

The Company attributes revenue to different geographic areas on the basis of the location of the customer.

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

	September 30, 2019		December 31, 2018
United States	$	79,437	$	64,560
Other		6,829		5,179
Total long-lived assets	$	86,266	$	69,739

Substantially all chemical materials were purchased from one supplier. See Note 10.