Business Segments, Geographic Information, and Major Customers Business Segments We operate in three reportable segments consisting of aviation, land and marine. Corporate expenses are allocated to the segments based on usage, where possible, or on other factors according to the nature of the activity. Our operating segments are determined based on the different markets in which we provide products and services, which are defined primarily by the customers and the products and services provided to those customers. Accordingly, our aviation, land and marine segments are organized based on the specific markets their functional business components serve, which are primarily businesses and governmental customers operating in those respective markets. In our aviation segment, we offer fuel and related products and services to major commercial airlines, second and third tier airlines, cargo carriers, regional and low cost carriers, airports, fixed based operators, corporate fleets, fractional operators, private aircraft, military fleets and the U.S. and foreign governments as well as intergovernmental organizations. In addition, we supply products and services to U.S. and foreign government, intergovernmental and military customers, such as the North Atlantic Treaty Organization (NATO) and the U.S. Defense Logistics Agency. In our land segment, we offer fuel, lubricants, power and natural gas solutions through Kinect, our global energy management services platform, and related products and services to customers including petroleum distributors operating in the land transportation market, retail petroleum operators, and industrial, commercial, residential and government customers. Our marine segment product and service offerings include fuel, lubricants and related products and services to a broad base of customers, including international container and tanker fleets, commercial cruise lines, yachts and time charter operators, offshore rig owners and operators, the U.S. and foreign governments as well as other fuel suppliers. Within each of our segments, we may enter into derivative contracts to mitigate the risk of market price fluctuations and also to offer our customers fuel pricing alternatives to meet their needs. Information concerning our revenue, gross profit, income from operations, depreciation and amortization and capital expenditures by segment is as follows (in millions): For the Year ended December 31, 2018 2017 2016 Revenue: Aviation segment $ 19,119.7 $ 14,538.2 $ 10,914.4 Land segment 11,381.1 10,958.0 8,918.8 Marine segment 9,249.5 8,199.3 7,182.5 $ 39,750.3 $ 33,695.5 $ 27,015.8 Gross profit: Aviation segment $ 507.8 $ 440.5 $ 401.0 Land segment 364.9 365.8 348.5 Marine segment 145.8 126.0 149.5 $ 1,018.5 $ 932.2 $ 899.0 Income from operations: Aviation segment $ 250.6 $ 192.9 $ 160.5 Land segment 47.8 (7.9 ) 70.8 Marine segment 37.8 (57.8 ) 30.2 336.3 127.2 261.5 Corporate overhead - unallocated (76.6 ) (81.6 ) (72.7 ) $ 259.7 $ 45.6 $ 188.9 Depreciation and amortization: Aviation segment $ 27.5 $ 26.8 $ 24.2 Land segment 46.5 49.8 47.1 Marine segment 2.2 5.8 6.6 Corporate 5.3 3.5 4.4 $ 81.5 $ 86.0 $ 82.3 Capital expenditures: Aviation segment $ 19.7 $ 12.3 $ 4.9 Land segment 30.9 21.0 12.3 Marine segment 2.9 1.5 6.1 Corporate 18.8 19.1 14.5 $ 72.3 $ 54.0 $ 37.7 (1) Includes a $17.1 million and $52.4 million of restructuring charges for the twelve month period ended 2018 and 2017, and a $12.8 million impairment charge attributable to certain long term assets in 2017 . (2) Includes a $79.1 million impairment charge attributable to the impairment of goodwill and other long term assets, and $1.4 million of restructuring charges in 2017 . Information concerning our accounts receivable, net, and total assets by segment is as follows (in millions): As of December 31, 2018 2017 Accounts receivable, net: Aviation segment, net of allowance for bad debt of $17.7 and $10.8 as of December 31, 2018 and December 31, 2017, respectively $ 992.2 $ 1,013.0 Land segment, net of allowance for bad debt of $2.7 and $6.6 as of December 31, 2018 and December 31, 2017, respectively 846.1 874.7 Marine segment, net of allowance for bad debt of $19.0 and $10.4 as of December 31, 2018 and December 31, 2017, respectively 901.2 817.9 $ 2,739.6 $ 2,705.6 Total assets: Aviation segment $ 2,261.0 $ 2,240.4 Land segment 2,178.1 2,091.4 Marine segment 1,124.2 1,097.1 Corporate 113.6 158.9 $ 5,676.9 $ 5,587.8 Geographic Information Information concerning our revenue and property and equipment, net, as segregated between the Americas, EMEA (Europe, Middle East and Africa) and the Asia Pacific regions, is presented as follows, based on the country of incorporation of the relevant subsidiary (in millions): For the Year ended December 31, 2018 2017 2016 Revenue: United States $ 20,555.5 $ 17,938.0 $ 14,368.8 EMEA (1) 9,721.9 7,553.3 6,018.6 Asia Pacific (2) 5,537.2 4,923.0 4,271.1 Americas, excluding United States 3,935.6 3,281.2 2,357.2 Total $ 39,750.3 $ 33,695.5 $ 27,015.8 As of December 31, 2018 2017 Property and equipment, net: United States $ 175.1 $ 152.6 EMEA 124.5 120.2 Asia Pacific 7.5 10.4 Americas, excluding United States 43.1 46.7 Total $ 350.3 $ 329.8 (1) Includes revenue related to the U.K. of $6.3 billion , $5.0 billion and $4.1 billion for 2018 , 2017 and 2016 , respectively. (2) Includes revenue related to Singapore of $5.4 billion , $4.8 billion and $4.2 billion for 2018 , 2017 and 2016 , respectively. Major Customers During each of the years presented on the consolidated statements of income and comprehensive income, none of our customers accounted for more than 10% of total consolidated revenue. Sales to government customers, which principally consist of sales to NATO in support of military operations in Afghanistan, have accounted for a material portion of our profitability in recent years. The profitability associated with our government business can be significantly impacted by supply disruptions, border closures, road blockages, hostility-related product losses, inventory shortages and other logistical difficulties that can arise when sourcing and delivering fuel in areas that are actively engaged in war or other military conflicts. Our sales to government customers may fluctuate significantly from time to time as a result of the foregoing factors, as well as the level of troop deployments and related activity in a particular region or area or the commencement, extension, renewal or completion of existing and new government contracts.