Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0000773910 (http://www.sec.gov/CIK)

Income Tax Disclosure [Abstract]	Period [Axis]
	2016-01-01 - 2016-12-31
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The following summarizes components of income tax expense (benefit) for the years ended December 31: millions 2016   2015   2014 Current           Federal $ (140 )   $ (177 )   $ 188 State (1 )   (18 )   2 Foreign 378   495   1,574   237   300   1,764 Deferred           Federal (1,020 )   (2,929 )   (389 ) State (148 )   (145 )   27 Foreign (90 )   (103 )   215   (1,258 )   (3,177 )   (147 ) Total income tax expense (benefit) $ (1,021 )   $ (2,877 )   $ 1,617
Schedule of Effective Income Tax Rate Reconciliation	The following summarizes the sources of these differences for the years ended December 31: millions except percentages 2016   2015   2014 Income (loss) before income taxes           Domestic $ (3,728 )   $ (9,155 )   $ (3,564 ) Foreign (101 )   (534 )   3,618 Total $ (3,829 )   $ (9,689 )   $ 54 U.S. federal statutory tax rate 35 %   35 %   35 % Tax computed at the U.S. federal statutory rate $ (1,340 )   $ (3,391 )   $ 19 Adjustments resulting from           State income taxes (net of federal income tax benefit) (108 )   (81 )   (11 ) Tax impact from foreign operations 80   299   62 Non-deductible Algerian exceptional profits tax 106   102   193 Net changes in uncertain tax positions 90   54   1,427 (Income) loss attributable to noncontrolling interests (92 )   42   (66 ) Dispositions of non-deductible goodwill 205   62   21 Other, net 38   36   (28 ) Total income tax expense (benefit) $ (1,021 )   $ (2,877 )   $ 1,617 Effective tax rate 27 %   30 %   2,994 %
Deferred Tax Assets (Liabilities) Table	The following summarizes components of total deferred taxes at December 31: millions 2016   2015 Federal $ (3,805 )   $ (4,721 ) State, net of federal (173 )   (248 ) Foreign (332 )   (431 ) Total deferred taxes $ (4,310 )   $ (5,400 ) The following summarizes tax effects of temporary differences that give rise to significant portions of the deferred tax assets (liabilities) at December 31: millions 2016   2015 Deferred tax liabilities       Oil and gas exploration and development operations $ (5,054 )   $ (5,643 ) Midstream and other depreciable properties (870 )   (1,049 ) Mineral operations (550 )   (492 ) Other (147 )   (470 ) Gross long-term deferred tax liabilities (6,621 )   (7,654 ) Deferred tax assets       Foreign and state net operating loss carryforwards 648   586 U.S. foreign tax credit carryforwards 1,834   1,254 Compensation and benefit plans 672   615 Mark to market on derivatives 324   441 Other 588   761 Gross long-term deferred tax assets 4,066   3,657 Valuation allowances on deferred tax assets not expected to be realized (1,755 )   (1,403 ) Net long-term deferred tax assets 2,311   2,254 Total deferred taxes $ (4,310 )   $ (5,400 )
Valuation Allowances on Deferred Tax Assets Rollforward	The following summarizes changes in the balance of valuation allowances on deferred tax assets: millions 2016   2015   2014 Balance at January 1 $ (1,403 )   $ (864 )   $ (818 ) Changes due to U.S. foreign tax credits (477 )   (384 )   11 Changes due to foreign and state net operating loss carryforwards 13   10   64 Changes due to foreign capitalized costs 112   (165 )   (121 ) Balance at December 31 $ (1,755 )   $ (1,403 )   $ (864 )
Schedule of Operating Loss Carryforwards	Tax carryforwards available for use on future income tax returns, prior to valuation allowance, at December 31, 2016, were as follows: millions Domestic   Foreign   Expiration Net operating loss—foreign $ —   $ 1,498   2017 - Indefinite Net operating loss—state $ 4,888   $ —   2017-2036
Schedule of Tax Credit Carryforwards	Tax carryforwards available for use on future income tax returns, prior to valuation allowance, at December 31, 2016, were as follows: millions Domestic   Foreign   Expiration Foreign tax credits $ 1,834   $ —   2023-2027 Texas margins tax credit $ 34   $ —   2026
Taxes Receivable (Payable) Table	The following summarizes taxes receivable (payable) related to income tax expense (benefit) at December 31: millions         Balance Sheet Classification   2016   2015 Income taxes receivable         Accounts receivable—other   $ 180   $ 1,046 Other assets   67   61     247   1,107 Income taxes (payable)         Accrued expense   (6 )   (9 ) Total net income taxes receivable (payable)   $ 241   $ 1,098
Unrecognized Tax Benefits Rollforward	Changes in the balance of unrecognized tax benefits excluding interest and penalties on uncertain tax positions were as follows:   Assets (Liabilities) millions 2016   2015   2014 Balance at January 1 $ (1,780 )   $ (1,687 )   $ (147 ) Increases related to prior-year tax positions (86 )   (99 )   (11 ) Decreases related to prior-year tax positions 436   89   39 Increases related to current-year tax positions (26 )   (263 )   (1,568 ) Settlements —   180   — Balance at December 31 $ (1,456 )   $ (1,780 )   $ (1,687 )
Tax Years Subject to Examination by Major Tax Jurisdiction Table	The following lists the tax years subject to examination by major tax jurisdiction:   Tax Years United States 2012-2015 Algeria 2012-2015 Ghana 2006-2015