Company Operations by Product, Customer and Geographic Area The Company has determined that we operate in one segment, the development and commercialization of pharmaceutical products, including controlled-release therapeutic products based on our proprietary polymer based technology. The Companys Chief Operating Decision Maker is the interim CEO. The interim CEO reviews profit and loss information on a consolidated basis to assess performance and make overall operating decisions as well as resource allocations. All products are included in one segment because the Companys products have similar economic and other characteristics, including the nature of the products and production processes, type of customers, distribution methods and regulatory environment. The following table presents a summary of total revenues by these products for the twelve months ended December 31, 2018 , 2017 , and 2016 : Revenue by Product: 2018 2017 2016 Bloxiverz $ 20,850 $ 45,596 $ 82,896 Vazculep 42,916 38,187 39,796 Akovaz 33,759 80,617 16,831 Noctiva 1,204   Other 2,694 8,441 7,699 Total product sales 101,423 172,841 147,222 License revenue 1,846 404 3,024 Total revenues $ 103,269 $ 173,245 $ 150,246 Concentration of credit risk with respect to accounts receivable is limited due to the high credit quality comprising a significant portion of the Companys customers. Management periodically monitors the creditworthiness of our customers and believes that we have adequately provided for any exposure to potential credit loss. The following table presents a summary of total revenues by significant customer for the twelve months ended December 31, 2018 , 2017 , and 2016 : Revenue by Significant Customer: 2018 2017 2016 Customer A $ 26,794 $ 44,762 $ 51,648 Customer B 25,413 37,965 39,359 Customer C 18,620 25,691 30,916 Customer D 9,653 53,342 17,728 Others 20,943 11,081 7,571 Total product sales 101,423 172,841 147,222 License revenue 1,846 404 3,024 Total revenues $ 103,269 $ 173,245 $ 150,246 As of December 31, 2018 , the Company had four customers, each of which are substantial wholesale distributors, and accounted for 10% or more of the accounts receivable balance. One customer accounted for 32% , or $3,571 , a second customer accounted for 24% or $2,755 , a third customer accounted for 24% or $2,789 , and a fourth customer accounted for 10% or $1,174 . As of December 31, 2018 , the Company had no significant past due account receivable balances. The following table summarizes revenues by geographic region for the twelve months ended December 31, 2018 , 2017 , and 2016 : Revenue by Geographic Region: 2018 2017 2016 United States $ 101,423 $ 172,841 $ 147,283 Ireland 1,846 404 2,963 Total revenues $ 103,269 $ 173,245 $ 150,246 Currently we depend on a single contract manufacturing organization for the manufacture of Bloxiverz, Vazculep and Noctiva and two contract manufacturing organizations for the manufacture of Akovaz, from which we derive a majority of our revenues. Additionally, we purchase certain raw materials used in our products from a limited number of suppliers, including a single supplier for certain key ingredients. Non-monetary long-lived assets primarily consist of property and equipment, goodwill and intangible assets. The following table summarizes non-monetary long-lived assets by geographic region as of December 31, 2018 , 2017 , and 2016 : Long-lived Assets by Geographic Region: 2018 2017 2016 United States $ 27,761 $ 116,536 $ 42,021 France 1,365 2,257 2,524 Ireland 6,028 1,360 202 Total $ 35,154 $ 120,153 $ 44,747