Segment Information (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016		Mar. 31, 2015
Segment Reporting Information [Line Items]
Sales and other operating revenues		$ 714		$ 1,280
Marketing revenues		58		204
Total revenues		772		1,484
Income from equity method investments		14		36
Net gain ( loss) on disposal of assets and other income		(56)		12
Production expenses		328		444
Marketing costs		58		205
Exploration Expenses		24		90
Depreciation, depletion and amortization		609		821
Impairment of Oil and Gas Properties		1		0
Other expenses		260	[1]	278
Taxes other than income		48		67
Net interest and other		85		47
Income tax provision (benefit)		(276)		(144)
Segment income (loss) /Loss from continuing operations		(407)		(276)
Capital expenditures	[2]	359		1,102
North America Exploration and Production [Member]
Segment Reporting Information [Line Items]
Sales and other operating revenues		493		850
Marketing revenues		31		178
Total revenues		524		1,028
Income from equity method investments		0		0
Net gain ( loss) on disposal of assets and other income		1		0
Production expenses		134		202
Marketing costs		32		180
Exploration Expenses		18		35
Depreciation, depletion and amortization		487		683
Impairment of Oil and Gas Properties		1
Other expenses		118	[1]	117
Taxes other than income		42		61
Net interest and other		0		0
Income tax provision (benefit)		(112)		(89)
Segment income (loss) /Loss from continuing operations		(195)		(161)
Capital expenditures	[2]	315		933
International Exploration and Production [Member]
Segment Reporting Information [Line Items]
Sales and other operating revenues		96		182
Marketing revenues		15		26
Total revenues		111		208
Income from equity method investments		14		36
Net gain ( loss) on disposal of assets and other income		6		10
Production expenses		53		67
Marketing costs		14		25
Exploration Expenses		6		55
Depreciation, depletion and amortization		50		64
Impairment of Oil and Gas Properties		0
Other expenses		16	[1]	23
Taxes other than income		0		0
Net interest and other		0		0
Income tax provision (benefit)		(12)		(3)
Segment income (loss) /Loss from continuing operations		4		23
Capital expenditures	[2]	32		146
Oil Sands Mining Segment [Member]
Segment Reporting Information [Line Items]
Sales and other operating revenues		148		225
Marketing revenues		12		0
Total revenues		160		225
Income from equity method investments		0		0
Net gain ( loss) on disposal of assets and other income		0		1
Production expenses		141		175
Marketing costs		12		0
Exploration Expenses		0		0
Depreciation, depletion and amortization		60		62
Impairment of Oil and Gas Properties		0
Other expenses		7	[1]	9
Taxes other than income		5		5
Net interest and other		0		0
Income tax provision (benefit)		(17)		(6)
Segment income (loss) /Loss from continuing operations		(48)		(19)
Capital expenditures	[2]	9		21
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Sales and other operating revenues		(23)	[3]	23	[4]
Marketing revenues		0		0
Total revenues		(23)		23
Income from equity method investments		0		0
Net gain ( loss) on disposal of assets and other income		(63)	[5]	1
Production expenses		0		0
Marketing costs		0		0
Exploration Expenses		0		0
Depreciation, depletion and amortization		12		12
Impairment of Oil and Gas Properties		0
Other expenses	[1]	119	[6]	129	[7]
Taxes other than income		1		1
Net interest and other		85		47
Income tax provision (benefit)		(135)		(46)
Segment income (loss) /Loss from continuing operations		(168)		(119)
Capital expenditures	[2]	3		2
Workforce reduction		7		43
United States and Foreign Pension Plans Defined Benefit [Member]
Segment Reporting Information [Line Items]
Net settlement loss	[8]	48		17
United States and Foreign Pension Plans Defined Benefit [Member] | Corporate and Other [Member]
Segment Reporting Information [Line Items]
Net settlement loss	[8]	$ 48		$ 17

[1] Includes other operating expenses and general and administrative expenses.

[2] Includes accruals.

[3] Unrealized loss on commodity derivative instruments.

[4] Unrealized gain on commodity derivative instruments.

[5] Related to the net loss on disposal of assets (see Note 5).

[6] Includes pension settlement loss of $48 million and severance related expenses associated with workforce reductions of $7 million (see Note 7).

[7] Includes $43 million of severance related expenses associated with a workforce reduction and pension settlement loss of $17 million (see Note 7).

[8] Settlements are recognized as they occur, once it is probable that lump sum payments from a plan for a given year will exceed the plan's total service and interest cost for that year.