SEGMENT REPORTING We operate primarily through three business segments: diagnostic and information technology-based products and services for the veterinary market, which we refer to as CAG; water quality products (Water); and diagnostic products and services for livestock and poultry health and to ensure the quality and safety of milk and food, which we refer to as LPD. Our Other operating segment combines and presents products for the human point-of-care medical diagnostics market with our out-licensing arrangements because they do not meet the quantitative or qualitative thresholds for reportable segments. Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision-maker, or decision-making group, in deciding how to allocate resources and in assessing performance. Our chief operating decision-maker is our Chief Executive Officer. Our reportable segments include: CAG, Water, LPD, and Other. Assets are not allocated to segments for internal reporting purposes. CAG develops, designs, manufactures and distributes products and performs services for veterinarians and the biomedical analytics market, primarily related to diagnostics and information management. Water develops, designs, manufactures and distributes a range of products used in the detection of various microbiological parameters in water. LPD develops, designs, manufactures and distributes diagnostic tests and related instrumentation and performs services that are used to manage the health status of livestock and poultry, to improve dairy efficiency, and to ensure the quality and safety of milk and food. OPTI Medical manufactures and distributes point-of-care electrolyte and blood gas analyzers and related consumable products for the human medical diagnostics market. Intersegment revenues, which are not included in the table below, were not material for the years ended December 31, 2018 , 2017 and 2016 . Certain costs are not allocated to our reportable segments and are instead reported under the caption Unallocated Amounts. These costs include costs that do not align with one of our existing operating segments or are cost prohibitive to allocate, which primarily consist of our R&amp;D function, regional or country expenses, certain foreign currency revaluation gains and losses on monetary balances in currencies other than our subsidiaries functional currency and unusual items. Corporate support function costs (such as information technology, facilities, human resources, finance and legal), health benefits and incentive compensation are charged to our business segments at pre-determined budgeted amounts or rates. Differences from these pre-determined budgeted amounts or rates are captured within Unallocated Amounts. Below is our segment information ( in thousand s): For the Years Ended December 31, CAG Water LPD Other Unallocated Amounts Consolidated Total 2018 Revenue $ 1,935,428 $ 125,198 $ 130,581 $ 22,035 $  $ 2,213,242 ? Income (loss) from operations $ 429,483 $ 56,607 $ 19,412 $ 3,729 $ (17,896 ) $ 491,335 Interest expense, net (33,593 ) Income before provision for income taxes 457,742 Provision for income taxes 80,695 Net income 377,047 Less: Net income attributable to noncontrolling interest 16 Net income attributable to IDEXX Laboratories, Inc. stockholders $ 377,031 Depreciation and amortization $ 72,789 $ 2,592 $ 4,094 $ 3,703 $  $ 83,178 Expenditures for long-lived assets (1) $ 103,300 $ 3,172 $ 4,787 $ 4,492 $  $ 115,751 ? 2017 Revenue $ 1,703,377 $ 114,395 $ 128,481 $ 22,805 $  $ 1,969,058 ? Income (loss) from operations $ 363,557 $ 50,616 $ 16,464 $ 4,837 $ (22,446 ) $ 413,028 Interest expense, net (31,971 ) Income before provision for income taxes 381,057 Provision for income taxes 117,788 Net income 263,269 Less: Net income attributable to noncontrolling interest 125 Net income attributable to IDEXX Laboratories, Inc. stockholders $ 263,144 Depreciation and amortization $ 71,835 $ 2,856 $ 5,052 $ 3,397 $  $ 83,140 Expenditures for long-lived assets (1) $ 64,759 $ 2,573 $ 3,021 $ 4,031 $  $ 74,384 ? 2016 Revenue $ 1,522,689 $ 103,579 $ 126,491 $ 22,664 $  $ 1,775,423 Income (loss) from operations $ 301,342 $ 45,702 $ 18,914 $ 884 $ (16,603 ) $ 350,239 Interest expense, net (28,393 ) Income before provision for income taxes 321,846 Provision for income taxes 99,792 Net income 222,054 Less: Net income attributable to noncontrolling interest 9 Net income attributable to IDEXX Laboratories, Inc. stockholders $ 222,045 Depreciation and amortization $ 64,878 $ 3,098 $ 5,543 $ 4,699 $  $ 78,218 Expenditures for long-lived assets (1) $ 56,329 $ 2,102 $ 4,824 $ 1,532 $  $ 64,787 (1) Expenditures for long-lived assets exclude expenditures for intangible assets. See "Note 4 . Acquisitions and Investments " for information regarding acquisitions of intangible assets during the years ended December 31, 2018 , 2017 and 2016 . See "Note 3. Revenue Recognition " for a summary of disaggregated revenue by reportable segment and by major product and service category for the years ended December 31, 2018, 2017 and 2016. Net long-lived assets, consisting of net property and equipment, are subject to geographic risks because they are generally difficult to move and to effectively utilize in another geographic area in a reasonable time period and because they are relatively illiquid. Net long-lived assets by principal geographic areas were as follows (in thousands) : ? December 31, 2018 December 31, 2017 Americas United States $ 348,240 $ 310,696 Brazil 16,735 17,030 Canada 1,859 2,238 ? 366,834 329,964 Europe, the Middle East and Africa Germany 25,036 7,522 United Kingdom 11,517 11,528 Netherlands 10,273 8,225 France 2,130 2,305 Switzerland 2,742 1,755 Other 3,763 3,838 ? 55,461 35,173 Asia Pacific Region Japan 5,296 4,065 Australia 4,257 4,426 Other 5,422 5,468 ? 14,975 13,959 Total $ 437,270 $ 379,096