Equity - AOCI Reclassifications Table (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Oil, natural gas and NGL Reclassifications from AOCI	$ 728	$ 1,704	$ 1,813	$ 3,471
Net gain (loss) on Sales of Investments Reclassifications from AOCI	0	0	0	67
Total Reclassification from AOCI	(4,090)	230	(7,810)	696
Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total Reclassification from AOCI	3	(1)	13	5
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gain (loss) on Sales of Investments Reclassifications from AOCI			(5)
Commodity Contract [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Oil, natural gas and NGL Reclassifications from AOCI	$ 3	$ (1)	$ 13	$ 10