Oil and Gas Exploration and Production Industries Disclosures, Discounted Future Net Cash Flows (Details) - USD ($) $ in Thousands |
12 Months Ended | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
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| Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items] | ||||||||||||||||||
| Future cash inflows | $ 58,840,424 | [1] | $ 68,720,648 | [2] | $ 146,950,221 | [3] | ||||||||||||
| Future production costs | (28,018,883) | (32,060,855) | (51,633,293) | |||||||||||||||
| Future development costs | (12,741,932) | (15,785,811) | (20,494,765) | |||||||||||||||
| Future income taxes | (3,211,320) | (4,616,201) | (23,185,714) | |||||||||||||||
| Future net cash flows | 14,868,289 | 16,257,781 | 51,636,449 | |||||||||||||||
| Discount to present value at 10% annual rate | (6,056,132) | (6,636,385) | (23,713,031) | |||||||||||||||
| Standardized measure of discounted future net cash flows relating to proved oil and gas reserves | $ 9,621,396 | $ 27,923,418 | $ 21,333,432 | 8,812,157 | 9,621,396 | 27,923,418 | ||||||||||||
| Annual Rate of Discount to Present Value | 10.00% | 10.00% | 10.00% | |||||||||||||||
| Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward] | ||||||||||||||||||
| Balance at Beginning of Period | $ 9,621,396 | $ 27,923,418 | $ 21,333,432 | |||||||||||||||
| Sales and transfers of oil and gas produced, net of production costs | (3,478,625) | (4,020,717) | (9,470,714) | |||||||||||||||
| Net changes in prices and production costs | (3,679,602) | (30,669,350) | 1,263,177 | |||||||||||||||
| Extensions, discoveries, additions and improved recovery, net of related costs | 907,267 | 1,095,898 | 8,083,852 | |||||||||||||||
| Development costs incurred | 1,230,000 | 2,137,700 | 2,835,100 | |||||||||||||||
| Revisions of estimated development cost | 2,121,708 | 4,079,381 | 1,802,735 | |||||||||||||||
| Revisions of previous quantity estimates | 1,053,020 | (4,051,874) | 1,812,532 | |||||||||||||||
| Accretion of discount | 1,054,435 | 3,857,479 | 2,833,350 | |||||||||||||||
| Net change in income taxes | 868,038 | 9,728,423 | (3,651,300) | |||||||||||||||
| Purchases of reserves in place | 377,872 | 123,542 | 317,785 | |||||||||||||||
| Sales of reserves in place | (375,793) | (37,088) | (478,879) | |||||||||||||||
| Changes in timing and other | (887,559) | (545,416) | 1,242,348 | |||||||||||||||
| Balance at End of Period | 8,812,157 | 9,621,396 | 27,923,418 | |||||||||||||||
| United States | ||||||||||||||||||
| Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items] | ||||||||||||||||||
| Future cash inflows | 57,913,314 | [1] | 67,242,928 | [2] | 144,355,692 | [3] | ||||||||||||
| Future production costs | (27,625,833) | (31,707,743) | (51,112,604) | |||||||||||||||
| Future development costs | (12,602,699) | (15,579,923) | (20,270,439) | |||||||||||||||
| Future income taxes | (3,151,319) | (4,400,542) | (22,725,618) | |||||||||||||||
| Future net cash flows | 14,533,463 | 15,554,720 | 50,247,031 | |||||||||||||||
| Discount to present value at 10% annual rate | (6,039,736) | (6,589,253) | (23,542,990) | |||||||||||||||
| Standardized measure of discounted future net cash flows relating to proved oil and gas reserves | 8,965,467 | 26,704,041 | 19,576,901 | 8,493,727 | 8,965,467 | 26,704,041 | ||||||||||||
| Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward] | ||||||||||||||||||
| Balance at Beginning of Period | 8,965,467 | 26,704,041 | 19,576,901 | |||||||||||||||
| Sales and transfers of oil and gas produced, net of production costs | (3,260,372) | (3,685,600) | (8,874,180) | |||||||||||||||
| Net changes in prices and production costs | (3,352,802) | (29,993,699) | 1,481,668 | |||||||||||||||
| Extensions, discoveries, additions and improved recovery, net of related costs | 865,066 | 1,028,410 | 8,074,550 | |||||||||||||||
| Development costs incurred | 1,207,000 | 2,135,800 | 2,818,800 | |||||||||||||||
| Revisions of estimated development cost | 2,092,769 | 4,087,093 | 1,696,916 | |||||||||||||||
| Revisions of previous quantity estimates | 1,013,753 | (4,084,572) | 1,741,918 | |||||||||||||||
| Accretion of discount | 970,388 | 3,699,330 | 2,612,286 | |||||||||||||||
| Net change in income taxes | 738,416 | 9,550,847 | (3,743,300) | |||||||||||||||
| Purchases of reserves in place | 377,872 | 123,542 | 317,785 | |||||||||||||||
| Sales of reserves in place | (375,793) | (23,424) | (189,808) | |||||||||||||||
| Changes in timing and other | (748,037) | (576,301) | 1,190,505 | |||||||||||||||
| Balance at End of Period | 8,493,727 | 8,965,467 | 26,704,041 | |||||||||||||||
| Trinidad | ||||||||||||||||||
| Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items] | ||||||||||||||||||
| Future cash inflows | 524,523 | [1] | 954,779 | [2] | 1,615,280 | [3] | ||||||||||||
| Future production costs | (165,757) | (183,607) | (277,844) | |||||||||||||||
| Future development costs | (103,631) | (140,541) | (84,576) | |||||||||||||||
| Future income taxes | (60,001) | (215,659) | (460,096) | |||||||||||||||
| Future net cash flows | 195,134 | 414,972 | 792,764 | |||||||||||||||
| Discount to present value at 10% annual rate | (9,384) | (33,848) | (110,228) | |||||||||||||||
| Standardized measure of discounted future net cash flows relating to proved oil and gas reserves | 381,124 | 682,536 | 876,640 | 185,750 | 381,124 | 682,536 | ||||||||||||
| Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward] | ||||||||||||||||||
| Balance at Beginning of Period | 381,124 | 682,536 | 876,640 | |||||||||||||||
| Sales and transfers of oil and gas produced, net of production costs | (215,414) | (351,606) | (473,757) | |||||||||||||||
| Net changes in prices and production costs | (182,876) | (370,503) | (12,079) | |||||||||||||||
| Extensions, discoveries, additions and improved recovery, net of related costs | 42,201 | 47,613 | 3,113 | |||||||||||||||
| Development costs incurred | 3,900 | 500 | 12,800 | |||||||||||||||
| Revisions of estimated development cost | 22,596 | (34,647) | 9,981 | |||||||||||||||
| Revisions of previous quantity estimates | 36,648 | 33,285 | 35,001 | |||||||||||||||
| Accretion of discount | 56,566 | 104,464 | 133,019 | |||||||||||||||
| Net change in income taxes | 129,622 | 177,576 | 91,438 | |||||||||||||||
| Purchases of reserves in place | 0 | 0 | 0 | |||||||||||||||
| Sales of reserves in place | 0 | 0 | 0 | |||||||||||||||
| Changes in timing and other | (88,617) | 91,906 | 6,380 | |||||||||||||||
| Balance at End of Period | 185,750 | 381,124 | 682,536 | |||||||||||||||
| Other International (1) | ||||||||||||||||||
| Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves [Line Items] | ||||||||||||||||||
| Future cash inflows | [4] | 402,587 | [1] | 522,941 | [2] | 979,249 | [3] | |||||||||||
| Future production costs | [4] | (227,293) | (169,505) | (242,845) | ||||||||||||||
| Future development costs | [4] | (35,602) | (65,347) | (139,750) | ||||||||||||||
| Future income taxes | [4] | 0 | 0 | 0 | ||||||||||||||
| Future net cash flows | [4] | 139,692 | 288,089 | 596,654 | ||||||||||||||
| Discount to present value at 10% annual rate | [4] | (7,012) | (13,284) | (59,813) | ||||||||||||||
| Standardized measure of discounted future net cash flows relating to proved oil and gas reserves | [4] | 274,805 | 536,841 | 879,891 | $ 132,680 | $ 274,805 | $ 536,841 | |||||||||||
| Increase (Decrease) in Standardized Measure of Discounted Future Net Cash Flow Relating to Proved Oil and Gas Reserves [Roll Forward] | ||||||||||||||||||
| Balance at Beginning of Period | [4] | 274,805 | 536,841 | 879,891 | ||||||||||||||
| Sales and transfers of oil and gas produced, net of production costs | [4] | (2,839) | 16,489 | (122,777) | ||||||||||||||
| Net changes in prices and production costs | [4] | (143,924) | (305,148) | (206,412) | ||||||||||||||
| Extensions, discoveries, additions and improved recovery, net of related costs | [4] | 0 | 19,875 | 6,189 | ||||||||||||||
| Development costs incurred | [4] | 19,100 | 1,400 | 3,500 | ||||||||||||||
| Revisions of estimated development cost | [4] | 6,343 | 26,935 | 95,838 | ||||||||||||||
| Revisions of previous quantity estimates | [4] | 2,619 | (587) | 35,613 | ||||||||||||||
| Accretion of discount | [4] | 27,481 | 53,685 | 88,045 | ||||||||||||||
| Net change in income taxes | [4] | 0 | 0 | 562 | ||||||||||||||
| Purchases of reserves in place | [4] | 0 | 0 | 0 | ||||||||||||||
| Sales of reserves in place | [4] | 0 | (13,664) | (289,071) | ||||||||||||||
| Changes in timing and other | [4] | (50,905) | (61,021) | 45,463 | ||||||||||||||
| Balance at End of Period | [4] | $ 132,680 | $ 274,805 | $ 536,841 | ||||||||||||||
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