Other Current Liabilities - Details of Other Current Liabilities (Detail) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Accrued operating expenses	$ 140	$ 163
Accrued exploration and development	682	1,606
Accrued compensation and benefits	150	204
Accrued interest	155	160
Accrued income taxes	352	54
Current asset retirement obligation	28	37
Other	166	230
Total Other current liabilities	$ 1,673	$ 2,454