Segment Reporting Historically, our three reporting segments have been: (i) crude oil marketing, transportation and storage, (ii) tank truck transportation of liquid chemicals and dry bulk, and (iii) upstream crude oil and natural gas exploration and production. Our upstream crude oil and natural gas exploration and production wholly owned subsidiary filed for bankruptcy in April 2017 (see Note 4 for further information), and as a result of our loss of control of the wholly owned subsidiary, AREC was deconsolidated and is accounted for under the cost method of accounting. AREC remained a reportable segment until its deconsolidation, effective April 30, 2017. Information concerning our various business activities was follows for the periods indicated (in thousands): Reporting Segments Marketing Transportation Oil and Gas and Other Total Year Ended December 31, 2018 Revenues $ 1,694,437 $ 55,776 $  $ 1,750,213 Segment operating (losses) earnings (1) 7,008 3,337  10,345 Depreciation, depletion and amortization 6,384 4,270  10,654 Property and equipment additions (3) (4) 1,540 10,178 13 11,731 Year Ended December 31, 2017 Revenues $ 1,267,275 $ 53,358 $ 1,427 $ 1,322,060 Segment operating (losses) earnings (1) (2) 11,700 (544) 53 11,209 Depreciation, depletion and amortization 7,812 5,364 423 13,599 Property and equipment additions (3) 468 351 1,825 2,644 Year Ended December 31, 2016 Revenues $ 1,043,775 $ 52,355 $ 3,410 $ 1,099,540 Segment operating (losses) earnings (1) 17,045 (48) (533) 16,464 Depreciation, depletion and amortization 9,997 7,249 1,546 18,792 Property and equipment additions 1,321 6,868 295 8,484 _________________ (1) Our crude oil marketing segments operating earnings included inventory valuation losses of $5.4 million for the year ended December 31, 2018, and inventory liquidation gains of $3.3 million and $8.2 million for the years ended December 31, 2017 and 2016, respectively. (2) Segment operating (losses) earnings includes approximately $0.4 million of costs related to a voluntary early retirement program that was implemented in August 2017. (3) Our crude oil marketing segments property and equipment additions do not include approximately $2.9 million and $1.8 million of tractors acquired during the years ended December 31, 2018 and 2017, respectively, under capital leases. See Note 15 for further information. (4) During the year ended December 31, 2018, we had $13 thousand of property and equipment additions for leasehold improvements at our corporate headquarters, which is not attributed or allocated to any of our reporting segments. Segment operating earnings reflect revenues net of operating costs and depreciation, depletion and amortization expense and are reconciled to earnings (losses) before income taxes and investment in unconsolidated affiliate, as follows for the periods indicated (in thousands): Year Ended December 31, 2018 2017 2016 Segment operating earnings $ 10,345 $ 11,209 $ 16,464 General and administrative (1) (8,937) (9,707) (10,410) Operating earnings (losses) 1,408 1,502 6,054 Loss on deconsolidation of subsidiary  (3,505)  Impairment of investment in unconsolidated affiliate  (2,500)  Interest income 2,155 1,103 582 Interest expense (109) (27) (2) (Losses) earnings before income taxes and investment in unconsolidated affiliate $ 3,454 $ (3,427) $ 6,634 _______________ (1) General and administrative expenses for the year ended December 31, 2017 included approximately $1.0 million of costs related to a voluntary early retirement program we implemented in August 2017. Identifiable assets by industry segment were as follows at the dates indicated (in thousands): December 31, 2018 2017 2016 Reporting segment: Marketing $ 119,370 $ 134,745 $ 107,257 Transportation 34,112 29,069 32,120 Oil and Gas (1)  425 7,279 Cash and other 125,388 118,465 100,216 Total assets $ 278,870 $ 282,704 $ 246,872 ____________________ (1) At December 31, 2017, amount represents our remaining cost method investment in this segment. See Note 4 for further information. There were no intersegment sales during the year ended December 31, 2018, and intersegment sales during the years ended December 31, 2017 and 2016 were insignificant. Other identifiable assets are primarily corporate cash, corporate accounts receivable, investments and properties not identified with any specific segment of our business. Accounting policies for transactions between reportable segments are consistent with applicable accounting policies as disclosed herein.