Note 11. Segment Information and Foreign Operations

Segment Information

We operate in one segment for the design, development, manufacture and distribution of high-performance compound and single element semiconductor substrates and sale of raw materials integral to these substrates. Our chief operating decision-maker has been identified as our Chief Executive Officer, who reviews operating results to make decisions about allocating resources and assessing performance for the Company. Since we operate in one segment, all financial segment and product line information can be found in the condensed consolidated financial statements.

Product Information

The following table represents revenue amounts (in thousands) by product type:


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2019		2018		2019		2018
Product Type:
Substrates	$	15,959	$	22,802	$	53,324	$	63,769
Raw Materials and Other		3,882		5,824		11,522		16,396
Total	$	19,841	$	28,626	$	64,846	$	80,165

Geographical Information

The following table represents revenue amounts (in thousands) reported for products shipped to customers in the corresponding geographic region:


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2019		2018		2019		2018
Geographical region:
China	$	5,117	$	10,268	$	21,870	$	26,271
Europe (primarily Germany)		4,737		4,879		13,752		17,957
Taiwan		4,399		6,116		12,062		15,445
Asia Pacific (excluding China, Taiwan and Japan)		2,234		2,334		6,156		6,399
North America (primarily the United States)		2,015		2,967		6,365		7,052
Japan		1,339		2,062		4,641		7,041
Total	$	19,841	$	28,626	$	64,846	$	80,165

Long-lived assets consist primarily of property, plant and equipment and operating lease right-of-use assets, and are attributed to the geographic location in which they are located. Long-lived assets, net of depreciation, by geographic region were as follows (in thousands):


	As of
	September 30,		December 31,
	2019		2018
Long-lived assets by geographic region, net of depreciation:
North America	$	1,174	$	445
China		91,487		81,835
	$	92,661	$	82,280

Significant Customers

One customer, Landmark, represented 16%, of our revenue for the three months ended September 30, 2019 and 2018. Our top five customers, although not the same five customers for each period, represented 40% and 39% of our revenue for the three months ended September 30, 2019 and 2018, respectively.

Two customers, Landmark and Haisi Optoelectronics, represented 14% and 10%, respectively, of our revenue for the nine months ended September 30, 2019 while one customer, Landmark, represented 13% of our revenue for the nine months ended September 30, 2018. Our top five customers, although not the same five customers for each period, represented 41% and 36% of our revenue for the nine months ended September 30, 2019 and 2018, respectively.

We perform ongoing credit evaluations of our customers’ financial condition, and limit the amount of credit extended when deemed necessary, but generally do not require collateral. Two customers accounted for 13% and 11% of our accounts receivable balance as of September 30, 2019, and three customers accounted for 17%, 12% and 10% of our accounts receivable as of December 31, 2018.