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Supplemental Oil and Gas Information (Tables) | 12 Months Ended
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Dec. 31, 2017
Reserve Quantities [Line Items] |
Costs Incurred in Oil and Gas Property Acquisition, Exploration and Development Activities |
﻿ |  |  |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |  |  |
﻿(Millions of dollars) | United States |  | Canada |  | Malaysia |  | Other |  | Total
﻿Year ended December 31, 2017 |  |  |  |  |  |  |  |  |  |
﻿Property acquisition costs |  |  |  |  |  |  |  |  |  |
﻿ Unproved | $ | 50.4 |  | – |  | – |  | 13.0 |  | 63.4
﻿ Proved |  | 7.7 |  | – |  | – |  | – |  | 7.7
﻿ Total acquisition costs |  | 58.1 |  | – |  | – |  | 13.0 |  | 71.1
﻿Exploration costs 1 |  | 13.7 |  | 0.6 |  | (8.9) |  | 73.8 |  | 79.2
﻿Development costs 1 |  | 508.4 |  | 273.8 |  | 35.7 |  | 1.1 |  | 819.0
﻿ Total costs incurred |  | 580.2 |  | 274.4 |  | 26.8 |  | 87.9 |  | 969.3
﻿Charged to expense |  |  |  |  |  |  |  |  |  |
﻿ Dry hole expense |  | (1.9) |  | – |  | 0.7 |  | (3.0) |  | (4.2)
﻿ Geophysical and other costs |  | 9.7 |  | 0.5 |  | 1.7 |  | 53.3 |  | 65.2
﻿ Total charged to expense |  | 7.8 |  | 0.5 |  | 2.4 |  | 50.3 |  | 61.0
﻿Property additions | $ | 572.4 |  | 273.9 |  | 24.4 |  | 37.6 |  | 908.3
﻿Year ended December 31, 2016 |  |  |  |  |  |  |  |  |  |
﻿Property acquisition costs |  |  |  |  |  |  |  |  |  |
﻿ Unproved | $ | 18.6 |  | – |  | – |  | – |  | 18.6
﻿ Proved |  | – |  | 206.7 |  | – |  | – |  | 206.7
﻿ Total acquisition costs |  | 18.6 |  | 206.7 |  | – |  | – |  | 225.3
﻿Exploration costs 1 |  | 18.5 |  | 3.6 |  | 6.0 |  | 42.0 |  | 70.1
﻿Development costs 1 |  | 239.7 |  | 165.1 |  | 102.9 |  | 0.3 |  | 508.0
﻿ Total costs incurred |  | 276.8 |  | 375.4 |  | 108.9 |  | 42.3 |  | 803.4
﻿Charged to expense |  |  |  |  |  |  |  |  |  |
﻿ Dry hole expense |  | 0.4 |  | – |  | 4.5 |  | 10.2 |  | 15.1
﻿ Geophysical and other costs |  | 5.7 |  | 3.6 |  | 0.7 |  | 33.4 |  | 43.4
﻿ Total charged to expense |  | 6.1 |  | 3.6 |  | 5.2 |  | 43.6 |  | 58.5
﻿Property additions | $ | 270.7 |  | 371.8 |  | 103.7 |  | (1.3) |  | 744.9
﻿Year ended December 31, 2015 |  |  |  |  |  |  |  |  |  |
﻿Property acquisition costs |  |  |  |  |  |  |  |  |  |
﻿ Unproved | $ | 10.1 |  | 2.5 |  | – |  | – |  | 12.6
﻿ Proved |  | – |  | – |  | – |  | – |  | –
﻿ Total acquisition costs |  | 10.1 |  | 2.5 | – | – |  | – |  | 12.6
﻿Exploration costs 1 |  | 166.8 |  | 0.7 |  | 69.0 |  | 135.4 |  | 371.9
﻿Development costs 1 |  | 1,375.1 |  | 231.5 |  | 210.0 |  | 2.8 |  | 1,819.4
﻿ Total costs incurred |  | 1,552.0 |  | 234.7 |  | 279.0 |  | 138.2 |  | 2,203.9
﻿Charged to expense |  |  |  |  |  |  |  |  |  |
﻿ Dry hole expense |  | 241.3 |  | – |  | 29.7 |  | 25.8 |  | 296.8
﻿ Geophysical and other costs |  | 16.9 |  | 0.7 |  | 7.9 |  | 73.2 |  | 98.7
﻿ Total charged to expense |  | 258.2 |  | 0.7 |  | 37.6 |  | 99.0 |  | 395.5
﻿Property additions | $ | 1,293.8 |  | 234.0 |  | 241.4 |  | 39.2 |  | 1,808.4
﻿ 1 Includes noncash asset retirement costs as follows:
﻿ |  |  |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |  |  |
﻿ 2017 |  |  |  |  |  |  |  |  |  |
﻿ Exploration costs | $ | – |  | – |  | – |  | – |  | –
﻿ Development costs |  | 37.6 |  | 6.3 |  | 8.4 |  | – |  | 52.3
﻿ | $ | 37.6 |  | 6.3 |  | 8.4 |  | – |  | 52.3
﻿ 2016 |  |  |  |  |  |  |  |  |  |
﻿ Exploration costs | $ | – |  | – |  | – |  | – |  | –
﻿ Development costs |  | 0.9 |  | 10.5 |  | 2.3 |  | – |  | 13.7
﻿ | $ | 0.9 |  | 10.5 |  | 2.3 |  | – |  | 13.7
﻿ 2015 |  |  |  |  |  |  |  |  |  |
﻿ Exploration costs | $ | – |  | – |  | – |  | – |  | –
﻿ Development costs |  | 30.7 |  | 49.1 |  | (3.0) |  | – |  | 76.8
﻿ | $ | 30.7 |  | 49.1 |  | (3.0) |  | – |  | 76.8
﻿
Results of Operations for Oil andGas Producing Activities |
﻿ |  |  |  |  |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |  |  |  |  |
﻿ |  |  |  | Canada |  |  |  |  |  |
﻿ | United |  | Conven- |  |  |  |  |  |  |  |
﻿(Millions of dollars) | States |  | tional |  | Synthetic |  | Malaysia |  | Other |  | Total
﻿Year ended December 31, 2017 |  |  |  |  |  |  |  |  |  |  |  |
﻿Revenues |  |  |  |  |  |  |  |  |  |  |  |
﻿ Crude oil and natural gas liquids sales | $ | 913.3 |  | 203.7 |  | – |  | 639.9 |  | – |  | 1,756.9
﻿ Natural gas sales |  | 37.9 |  | 155.1 |  | – |  | 138.2 |  | – |  | 331.2
﻿ Total oil and gas revenues |  | 951.2 |  | 358.8 |  | – |  | 778.1 |  | – |  | 2,088.1
﻿ Other operating revenues |  | 2.7 |  | 126.7 |  | – |  | 3.0 |  | – |  | 132.4
﻿ Total revenues |  | 953.9 |  | 485.5 |  | – |  | 781.1 |  | – |  | 2,220.5
﻿Costs and expenses |  |  |  |  |  |  |  |  |  |  |  |
﻿ Lease operating expenses |  | 198.5 |  | 101.1 |  | – |  | 168.8 |  | – |  | 468.4
﻿ Severance and ad valorem taxes |  | 42.2 |  | 1.5 |  | – |  | – |  | – |  | 43.7
﻿ Exploration costs charged to expense |  | 7.8 |  | 0.5 |  | – |  | 2.4 |  | 50.3 |  | 61.0
﻿ Undeveloped lease amortization |  | 60.2 |  | 1.6 |  | – |  | – |  | – |  | 61.8
﻿ Depreciation, depletion and amortization |  | 546.1 |  | 185.4 |  | – |  | 204.6 |  | 3.8 |  | 939.9
﻿ Accretion of asset retirement obligations |  | 17.4 |  | 7.9 |  | – |  | 17.3 |  | – |  | 42.6
﻿ Redetermination expense |  | – |  | – |  | – |  | 15.0 |  | – |  | 15.0
﻿ Selling and general expenses |  | 61.8 |  | 28.3 |  | – |  | 14.0 |  | 19.6 |  | 123.7
﻿ Other expenses |  | 20.0 |  | 2.3 |  | – |  | 8.4 |  | – |  | 30.7
﻿ Total costs and expenses |  | 954.0 |  | 328.6 |  | – |  | 430.5 |  | 73.7 |  | 1,786.8
﻿ Results of operations before taxes |  | (0.1) |  | 156.9 |  | – |  | 350.6 |  | (73.7) |  | 433.7
﻿ Income tax expense (benefit) |  | 2.5 |  | 44.4 |  | – |  | 126.4 |  | (36.2) |  | 137.1
﻿ Results of operations | $ | (2.6) |  | 112.5 |  | – |  | 224.2 |  | (37.5) |  | 296.6
﻿Year ended December 31, 2016 |  |  |  |  |  |  |  |  |  |  |  |
﻿Revenues |  |  |  |  |  |  |  |  |  |  |  |
﻿ Crude oil and natural gas liquids sales | $ | 650.7 |  | 171.7 |  | 60.7 |  | 623.7 |  | – |  | 1,506.8
﻿ Natural gas sales |  | 35.1 |  | 130.0 |  | – |  | 127.6 |  | – |  | 292.7
﻿ Total oil and gas revenues |  | 685.8 |  | 301.7 |  | 60.7 |  | 751.3 |  | – |  | 1,799.5
﻿ Other operating revenues |  | (0.1) |  | (0.7) |  | 3.6 |  | 2.1 |  | 0.2 |  | 5.1
﻿ Total revenues |  | 685.7 |  | 301.0 |  | 64.3 |  | 753.4 |  | 0.2 |  | 1,804.6
﻿Costs and expenses |  |  |  |  |  |  |  |  |  |  |  |
﻿ Lease operating expenses |  | 218.6 |  | 102.6 |  | 69.8 |  | 168.4 |  | – |  | 559.4
﻿ Severance and ad valorem taxes |  | 37.0 |  | 4.3 |  | 2.5 |  | – |  | – |  | 43.8
﻿ Exploration costs charged to expense |  | 6.1 |  | 3.6 |  | – |  | 5.2 |  | 43.6 |  | 58.5
﻿ Undeveloped lease amortization |  | 38.4 |  | 4.5 |  | – |  | – |  | 0.5 |  | 43.4
﻿ Depreciation, depletion and amortization |  | 600.5 |  | 186.7 |  | 16.5 |  | 227.7 |  | 5.9 |  | 1,037.3
﻿ Accretion of asset retirement obligations |  | 17.1 |  | 10.9 |  | 2.4 |  | 16.3 |  | – |  | 46.7
﻿ Impairment of assets |  | – |  | 95.1 |  | – |  | – |  | – |  | 95.1
﻿ Redetermination expense |  | – |  | – |  | – |  | 39.1 |  | – |  | 39.1
﻿ Selling and general expenses |  | 68.8 |  | 28.6 |  | 0.5 |  | 15.9 |  | 33.6 |  | 147.4
﻿ Other expenses (benefits) |  | (7.5) |  | 7.5 |  | – |  | 23.8 |  | (9.9) |  | 13.9
﻿ Total costs and expenses |  | 979.0 |  | 443.8 |  | 91.7 |  | 496.4 |  | 73.7 |  | 2,084.6
﻿ Results of operations before taxes |  | (293.3) |  | (142.8) |  | (27.4) |  | 257.0 |  | (73.5) |  | (280.0)
﻿ Income tax expense (benefit) |  | (87.9) |  | (58.9) |  | (75.4) |  | 85.9 |  | (18.8) |  | (155.1)
﻿ Results of operations | $ | (205.4) |  | (83.9) |  | 48.0 |  | 171.1 |  | (54.7) |  | (124.9)
1 Results exclude corporate overhead, interest and discontinued operations. ﻿ ﻿ ﻿ Schedule 5 – Results of Operations for Oil and Gas Producing Activities 1 – Continued ﻿ ﻿
﻿ |  |  |  |  |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |  |  |  |  |
﻿ |  |  |  | Canada |  |  |  |  |  |
﻿ | United |  | Conven- |  |  |  |  |  |  |  |
﻿(Millions of dollars) | States |  | tional |  | Synthetic |  | Malaysia |  | Other |  | Total
﻿Year ended December 31, 2015 |  |  |  |  |  |  |  |  |  |  |  |
﻿Revenues |  |  |  |  |  |  |  |  |  |  |  |
﻿ Crude oil and natural gas liquids sales | $ | 1,176.9 |  | 181.0 |  | 203.0 |  | 790.6 |  | – |  | 2,351.5
﻿ Natural gas sales |  | 70.4 |  | 167.7 |  | – |  | 185.4 |  | – |  | 423.5
﻿ Total oil and gas revenues |  | 1,247.3 |  | 348.7 |  | 203.0 |  | 976.0 |  | – |  | 2,775.0
﻿ Other operating revenues |  | 6.3 |  | (2.4) |  | 0.4 |  | 155.4 |  | – |  | 159.7
﻿ Total revenues |  | 1,253.6 |  | 346.3 |  | 203.4 |  | 1,131.4 |  | – |  | 2,934.7
﻿Costs and expenses |  |  |  |  |  |  |  |  |  |  |  |
﻿ Lease operating expenses |  | 312.0 |  | 102.4 |  | 166.0 |  | 251.9 |  | – |  | 832.3
﻿ Severance and ad valorem taxes |  | 55.9 |  | 4.8 |  | 5.1 |  | – |  | – |  | 65.8
﻿ Exploration costs charged to expense |  | 258.2 |  | 0.7 |  | – |  | 37.6 |  | 99.0 |  | 395.5
﻿ Undeveloped lease amortization |  | 59.2 |  | 14.4 |  | – |  | – |  | 1.8 |  | 75.4
﻿ Depreciation, depletion and amortization |  | 794.9 |  | 211.2 |  | 50.7 |  | 544.9 |  | 6.2 |  | 1,607.9
﻿ Accretion of asset retirement obligations |  | 20.2 |  | 7.2 |  | 5.4 |  | 15.9 |  | – |  | 48.7
﻿ Impairment of assets |  | 329.0 |  | 683.6 |  | – |  | 1,480.6 |  | – |  | 2,493.2
﻿ Selling and general expenses |  | 88.2 |  | 25.5 |  | 1.0 |  | 5.7 |  | 56.8 |  | 177.2
﻿ Other expenses |  | 288.7 |  | 43.9 |  | – |  | 15.9 |  | 12.1 |  | 360.6
﻿ Total costs and expenses |  | 2,206.3 |  | 1,093.7 |  | 228.2 |  | 2,352.5 |  | 175.9 |  | 6,056.6
﻿ Results of operations before taxes |  | (952.7) |  | (747.4) |  | (24.8) |  | (1,221.1) |  | (175.9) |  | (3,121.9)
﻿ Income tax expense (benefit) |  | (337.0) |  | (191.2) |  | 2.4 |  | (567.9) |  | (17.3) |  | (1,111.0)
﻿ Results of operations | $ | (615.7) |  | (556.2) |  | (27.2) |  | (653.2) |  | (158.6) |  | (2,010.9)
﻿ 1 Results exclude corporate overhead, interest and discontinued operations.
Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves |
﻿ |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |
﻿(Millions of dollars) | United States |  | Canada |  | Malaysia |  | Total
﻿December 31, 2017 |  |  |  |  |  |  |  |
﻿Future cash inflows | $ | 12,885.8 |  | 4,714.3 |  | 4,392.0 |  | 21,992.1
﻿Future development costs |  | (2,079.5) |  | (1,081.7) |  | (632.3) |  | (3,793.5)
﻿Future production costs |  | (4,765.3) |  | (2,507.4) |  | (2,305.0) |  | (9,577.7)
﻿Future income taxes |  | (893.7) |  | (161.1) |  | (232.2) |  | (1,287.0)
﻿ Future net cash flows |  | 5,147.3 |  | 964.1 |  | 1,222.5 |  | 7,333.9
﻿10% annual discount for estimated timing of cash flows |  | (2,698.2) |  | (394.6) |  | (318.2) |  | (3,411.0)
﻿ Standardized measure of discounted future net cash flows | $ | 2,449.1 |  | 569.5 |  | 904.3 |  | 3,922.9
﻿December 31, 2016 |  |  |  |  |  |  |  |
﻿Future cash inflows | $ | 9,477.9 |  | 3,752.7 |  | 4,318.7 |  | 17,549.3
﻿Future development costs |  | (1,691.1) |  | (1,143.6) |  | (763.8) |  | (3,598.5)
﻿Future production costs |  | (3,981.6) |  | (2,329.7) |  | (2,661.2) |  | (8,972.5)
﻿Future income taxes |  | (118.9) |  | (81.3) |  | (73.3) |  | (273.5)
﻿ Future net cash flows |  | 3,686.3 |  | 198.1 |  | 820.4 |  | 4,704.8
﻿10% annual discount for estimated timing of cash flows |  | (1,799.5) |  | (95.0) |  | (230.3) |  | (2,124.8)
﻿ Standardized measure of discounted future net cash flows | $ | 1,886.8 |  | 103.1 |  | 590.1 |  | 2,580.0
﻿December 31, 2015 |  |  |  |  |  |  |  |
﻿Future cash inflows | $ | 12,373.9 |  | 8,922.0 |  | 6,143.1 |  | 27,439.0
﻿Future development costs |  | (2,620.5) |  | (1,145.4) |  | (957.8) |  | (4,723.7)
﻿Future production costs |  | (4,955.4) |  | (5,892.7) |  | (3,290.5) |  | (14,138.6)
﻿Future income taxes |  | (339.7) |  | (504.8) |  | (216.2) |  | (1,060.7)
﻿ Future net cash flows |  | 4,458.3 |  | 1,379.1 |  | 1,678.6 |  | 7,516.0
﻿10% annual discount for estimated timing of cash flows |  | (2,430.0) |  | (666.8) |  | (560.1) |  | (3,656.9)
﻿ Standardized measure of discounted future net cash flows | $ | 2,028.3 |  | 712.3 |  | 1,118.5 |  | 3,859.1
﻿
Principal Sources of Change in the Standardized Measure of Discounted Future Net Cash Flows |
﻿ |  |  |  |  |  |
﻿ |  |  |  |  |  |
﻿(Millions of dollars) |  | 2017 |  | 2016 |  | 2015
﻿Net changes in prices and production costs | $ | 2,428.4 |  | (1,476.1) |  | (11,365.5)
﻿Net changes in development costs |  | (724.4) |  | 544.9 |  | 591.4
﻿Sales and transfers of oil and gas produced, net of production costs |  | (1,576.0) |  | (1,196.3) |  | (1,876.9)
﻿Net change due to extensions and discoveries |  | 807.9 |  | 280.5 |  | 1,145.8
﻿Net change due to purchases and sales of proved reserves |  | 85.9 |  | (583.4) |  | (287.4)
﻿Development costs incurred |  | 802.7 |  | 479.6 |  | 1,725.4
﻿Accretion of discount |  | 270.9 |  | 428.1 |  | 1,289.5
﻿Revisions of previous quantity estimates |  | (109.5) |  | (49.2) |  | 163.3
﻿Net change in income taxes |  | (643.0) |  | 292.8 |  | 2,568.3
﻿ Net increase (decrease) |  | 1,342.9 |  | (1,279.1) |  | (6,046.1)
﻿Standardized measure at January 1 |  | 2,580.0 |  | 3,859.1 |  | 9,905.2
﻿ Standardized measure at December 31 | $ | 3,922.9 |  | 2,580.0 |  | 3,859.1
﻿
Capitalized Costs Relating to Oil and Gas Producing Activities |
﻿ |  |  |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |  |  |
﻿(Millions of dollars) | United States |  | Canada |  | Malaysia |  | Other |  | Total
﻿December 31, 2017 |  |  |  |  |  |  |  |  |  |
﻿Unproved oil and gas properties | $ | 360.9 |  | 286.8 |  | 20.5 |  | 162.1 |  | 830.3
﻿Proved oil and gas properties |  | 9,606.4 |  | 3,603.4 |  | 6,139.7 |  | – |  | 19,349.5
﻿ Gross capitalized costs |  | 9,967.3 |  | 3,890.2 |  | 6,160.2 |  | 162.1 |  | 20,179.8
﻿Accumulated depreciation, depletion and amortization |  |  |  |  |  |  |  |  |  |
﻿ Unproved oil and gas properties |  | (149.5) |  | (230.7) |  | – |  | (21.8) |  | (402.0)
﻿ Proved oil and gas properties |  | (4,893.8) |  | (2,027.9) |  | (4,774.5) |  | – |  | (11,696.2)
﻿ Net capitalized costs | $ | 4,924.0 |  | 1,631.6 |  | 1,385.7 |  | 140.3 |  | 8,081.6
﻿December 31, 2016 |  |  |  |  |  |  |  |  |  |
﻿Unproved oil and gas properties | $ | 360.8 |  | 315.6 |  | 47.0 |  | 125.6 |  | 849.0
﻿Proved oil and gas properties |  | 9,384.6 |  | 4,241.6 |  | 6,147.8 |  | – |  | 19,774.0
﻿ Gross capitalized costs |  | 9,745.4 |  | 4,557.2 |  | 6,194.8 |  | 125.6 |  | 20,623.0
﻿Accumulated depreciation, depletion and amortization |  |  |  |  |  |  |  |  |  |
﻿ Unproved oil and gas properties |  | (151.2) |  | (233.6) |  | – |  | (21.8) |  | (406.6)
﻿ Proved oil and gas properties |  | (4,605.9) |  | (2,877.2) |  | (4,566.6) |  | – |  | (12,049.7)
﻿ Net capitalized costs | $ | 4,988.3 |  | 1,446.4 |  | 1,628.2 |  | 103.8 |  | 8,166.7
﻿
Oil Reserves [Member] |
Reserve Quantities [Line Items] |
Summary of Proved Reserves Based on Average Prices |
﻿ |  |  |  |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |  |  |  |
﻿ | Crude & Synthetic Oil |  | Crude Oil |  | Synthetic Oil 1
﻿(Millions of barrels) | Total |  | Total |  | United States |  | Canada |  | Malaysia |  | Canada
﻿Proved developed and undeveloped crude oil / synthetic oil reserves: |  |  |  |  |  |  |  |  |  |  |
﻿December 31, 2014 | 441.8 |  | 336.2 |  | 204.9 |  | 37.4 |  | 93.9 |  | 105.6
﻿Revisions of previous estimates | 5.3 |  | (8.2) |  | (7.6) |  | (4.8) |  | 4.2 |  | 13.5
﻿Improved recovery | 2.4 |  | 2.4 |  | – |  | – |  | 2.4 |  | –
﻿Extensions and discoveries | 63.8 |  | 63.8 |  | 63.8 |  | – |  | – |  | –
﻿Sales of properties | (11.0) |  | (11.0) |  | – |  | – |  | (11.0) |  | –
﻿Production | (46.1) |  | (41.8) |  | (22.2) |  | (4.7) |  | (14.9) |  | (4.3)
﻿December 31, 2015 | 456.2 |  | 341.4 |  | 238.9 |  | 27.9 |  | 74.6 |  | 114.8
﻿Revisions of previous estimates | (5.8) |  | (5.8) |  | (10.9) |  | 2.5 |  | 2.6 |  | –
﻿Extensions and discoveries | 11.0 |  | 11.0 |  | 8.6 |  | – |  | 2.4 |  | –
﻿Purchases of properties | 26.3 |  | 26.3 |  | – |  | 26.3 |  | – |  | –
﻿Sales of properties | (121.0) |  | (7.8) |  | (4.5) |  | (3.3) |  | – |  | (113.2)
﻿Production | (37.7) |  | (36.1) |  | (17.7) |  | (4.5) |  | (13.9) |  | (1.6)
﻿December 31, 2016 | 329.0 |  | 329.0 |  | 214.4 |  | 48.9 |  | 65.7 |  | (0.0)
﻿Revisions of previous estimates | (6.0) |  | (6.0) |  | (4.7) |  | 2.3 |  | (3.6) |  | –
﻿Improved recovery | 2.0 |  | 2.0 |  | – |  | – |  | 2.0 |  | –
﻿Extensions and discoveries | 31.6 |  | 31.6 |  | 27.2 |  | 4.4 |  | – |  | –
﻿Purchases of properties | 4.7 |  | 4.7 |  | 4.7 |  | – |  | – |  | –
﻿Production | (33.2) |  | (33.2) |  | (16.9) |  | (4.1) |  | (12.2) |  | –
﻿ December 31, 2017 | 328.1 |  | 328.1 |  | 224.7 |  | 51.5 |  | 51.9 |  | –
﻿Proved developed crude oil/ synthetic oil reserves: |  |  |  |  |  |  |  |  |  |  |
﻿ December 31, 2014 | 324.1 |  | 218.5 |  | 106.2 |  | 32.4 |  | 79.9 |  | 105.6
﻿ December 31, 2015 | 326.6 |  | 211.8 |  | 125.9 |  | 23.8 |  | 62.1 |  | 114.8
﻿ December 31, 2016 | 184.9 |  | 184.9 |  | 113.9 |  | 19.2 |  | 51.8 |  | –
﻿ December 31, 2017 | 185.5 |  | 185.5 |  | 126.3 |  | 21.9 |  | 37.3 |  | –
﻿Proved undeveloped crude oil reserves: |  |  |  |  |  |  |  |  |  |  |
﻿ December 31, 2014 | 117.7 |  | 117.7 |  | 98.7 |  | 5.0 |  | 14.0 |  | –
﻿ December 31, 2015 | 129.6 |  | 129.6 |  | 113.0 |  | 4.1 |  | 12.5 |  | –
﻿ December 31, 2016 | 144.1 |  | 144.1 |  | 100.5 |  | 29.7 |  | 13.9 |  | –
﻿ December 31, 2017 | 142.6 |  | 142.6 |  | 98.4 |  | 29.6 |  | 14.6 |  | –
﻿
Natural Gas Liquids Reserves [Member] |
Reserve Quantities [Line Items] |
Summary of Proved Reserves Based on Average Prices |
﻿ |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |
﻿(Millions of barrels) | Total |  | United States |  | Canada |  | Malaysia |
﻿Proved developed and undeveloped NGL reserves: |  |  |  |  |  |  |  |
﻿December 31, 2014 | 30.6 |  | 29.1 |  | 0.7 |  | 0.8 |
﻿Revisions of previous estimates | 2.0 |  | 2.2 |  | (0.3) |  | 0.1 |
﻿Extensions and discoveries | 7.6 |  | 7.6 |  | – |  | – |
﻿Sales of properties | (0.1) |  | – |  | – |  | (0.1) |
﻿Production | (3.7) |  | (3.5) |  | – |  | (0.2) |
﻿December 31, 2015 | 36.4 |  | 35.4 |  | 0.4 |  | 0.6 |
﻿Revisions of previous estimates | 1.6 |  | 1.2 |  | 0.2 |  | 0.2 |
﻿Extensions and discoveries | 2.9 |  | 2.8 |  | 0.1 |  | – |
﻿Purchases of properties | 5.1 |  | – |  | 5.1 |  | – |
﻿Production | (3.5) |  | (3.0) |  | (0.2) |  | (0.3) |
﻿December 31, 2016 | 42.5 |  | 36.4 |  | 5.6 |  | 0.5 |
﻿Revisions of previous estimates | 1.3 |  | 2.0 |  | (0.6) |  | (0.1) |
﻿Extensions and discoveries | 7.8 |  | 7.0 |  | 0.8 |  | – |
﻿Purchases of properties | 0.5 |  | 0.5 |  | – |  | – |
﻿Production | (3.2) |  | (2.9) |  | (0.2) |  | (0.1) |
﻿ December 31, 2017 | 48.9 |  | 43.0 |  | 5.6 |  | 0.3 |
﻿Proved developed NGL reserves: |  |  |  |  |  |  |  |
﻿ December 31, 2014 | 17.5 |  | 16.5 |  | 0.2 |  | 0.8 |
﻿ December 31, 2015 | 21.6 |  | 20.7 |  | 0.3 |  | 0.6 |
﻿ December 31, 2016 | 22.2 |  | 20.8 |  | 0.9 |  | 0.5 |
﻿ December 31, 2017 | 24.6 |  | 23.3 |  | 1.0 |  | 0.3 |
﻿Proved undeveloped NGL reserves: |  |  |  |  |  |  |  |
﻿ December 31, 2014 | 13.1 |  | 12.6 |  | 0.5 |  | – |
﻿ December 31, 2015 | 14.8 |  | 14.7 |  | 0.1 |  | – |
﻿ December 31, 2016 | 20.3 |  | 15.6 |  | 4.7 |  | – |
﻿ December 31, 2017 | 24.3 |  | 19.7 |  | 4.6 |  | – |
﻿
Natural Gas Reserves [Member] |
Reserve Quantities [Line Items] |
Summary of Proved Reserves Based on Average Prices |
﻿ |  |  |  |  |  |  |  |
﻿ |  |  |  |  |  |  |  |
﻿(Billions of cubic feet) | Total |  | United States |  | Canada |  | Malaysia |
﻿Proved developed and undeveloped natural gas reserves: |  |  |  |  |  |  |  |
﻿December 31, 2014 | 1,704.7 |  | 226.3 |  | 842.8 |  | 635.6 |
﻿Revisions of previous estimates | 53.5 |  | (5.2) |  | 18.9 |  | 39.8 |
﻿Improved recovery | 1.8 |  | – |  | – |  | 1.8 |
﻿Extensions and discoveries | 162.9 |  | 43.2 |  | 119.7 |  | – |
﻿Sales of properties | (78.0) |  | – |  | – |  | (78.0) |
﻿Production | (156.1) |  | (31.9) |  | (71.8) |  | (52.4) |
﻿December 31, 2015 | 1,688.8 |  | 232.4 |  | 909.6 |  | 546.8 |
﻿Revisions of previous estimates | 43.3 |  | 0.1 |  | 45.3 |  | (2.1) |
﻿Extensions and discoveries | 164.2 |  | 6.4 |  | 120.2 |  | 37.6 |
﻿Purchases of properties | 122.3 |  | – |  | 122.3 |  | – |
﻿Sales of properties | (2.2) |  | (0.1) |  | (2.1) |  | – |
﻿Production | (138.4) |  | (19.4) |  | (76.4) |  | (42.6) |
﻿December 31, 2016 | 1,878.0 |  | 219.4 |  | 1,118.9 |  | 539.7 |
﻿Revisions of previous estimates | (5.4) |  | (16.0) |  | 19.4 |  | (8.8) |
﻿Extensions and discoveries | 190.6 |  | 32.2 |  | 156.7 |  | 1.7 |
﻿Purchases of properties | 4.0 |  | 4.0 |  | – |  | – |
﻿Production | (140.1) |  | (16.3) |  | (82.6) |  | (41.2) |
﻿ December 31, 2017 | 1,927.1 |  | 223.3 |  | 1,212.4 |  | 491.4 |
﻿Proved developed natural gas reserves: |  |  |  |  |  |  |  |
﻿ December 31, 2014 | 812.1 |  | 145.6 |  | 467.4 |  | 199.1 |
﻿ December 31, 2015 | 783.5 |  | 148.3 |  | 453.5 |  | 181.7 |
﻿ December 31, 2016 | 818.1 |  | 138.7 |  | 498.9 |  | 180.5 |
﻿ December 31, 2017 | 819.3 |  | 127.7 |  | 547.0 |  | 144.6 |
﻿Proved undeveloped natural gas reserves: |  |  |  |  |  |  |  |
﻿ December 31, 2014 | 892.6 |  | 80.7 |  | 375.4 |  | 436.5 |
﻿ December 31, 2015 | 905.3 |  | 84.1 |  | 456.1 |  | 365.1 |
﻿ December 31, 2016 | 1,059.9 |  | 80.7 |  | 620.0 |  | 359.2 |
﻿ December 31, 2017 | 1,107.8 |  | 95.6 |  | 665.5 |  | 346.7 |
﻿

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