Dispositions - Additional Information (Detail) (USD $)	9 Months Ended		3 Months Ended	1 Months Ended	6 Months Ended	1 Months Ended	3 Months Ended		3 Months Ended		1 Months Ended	3 Months Ended	1 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Retail Business Disposal [Member]	Jun. 30, 2014 Electric Generating Facility [Member]	Jun. 30, 2014 Utica Shale [Member] acre	Apr. 30, 2014 Thailand [Member]	Mar. 31, 2014 Pangkah Asset [Member]	Mar. 31, 2014 Exploration Block Indonesia [Member]	Sep. 30, 2014 United Kingdom North Sea Cambo Asset [Member]	Sep. 30, 2014 Bayonne Energy Complex	Jan. 31, 2013 Beryl Fields And Scottish Area Gas Evacuation System Sage	Jun. 30, 2013 Samara-Nafta [Member]	Mar. 31, 2013 Azeri-Chirag-Guneshli (ACG) Fields [Member]	Mar. 31, 2013 Baku-Tbilisi-Ceyhan (BTC) Pipeline [Member]	Mar. 31, 2013 Baku Tbilisi Ceyhan Pipeline And Azeri Chirag Guneshli Fields
Dispositions [Abstract]
Consideration from sale of retail business			$ 2,800,000,000
Cash proceeds from asset sales	2,978,000,000	3,802,000,000		320,000,000	1,075,000,000	805,000,000	650,000,000		53,000,000	79,000,000	442,000,000	1,900,000,000			884,000,000
Gain (loss) on asset sale, pre-tax			954,000,000	13,000,000	62,000,000	706,000,000	31,000,000	(20,000,000)	33,000,000		328,000,000	1,119,000,000			360,000,000
Gain (loss) on asset sale, after-tax			602,000,000	8,000,000	35,000,000	706,000,000	(10,000,000)	11,000,000	33,000,000		323,000,000	1,119,000,000			360,000,000
Goodwill included in the divested businesses' net book value	126,000,000		115,000,000		11,000,000	76,000,000	56,000,000
Area of land sold					77,000
Cash proceeds from sale of subsidiary												2,100,000,000
Net gain on sale attributable to noncontrolling interest holder's share												168,000,000
Net gain on sale attributable to parent												$ 951,000,000
Corporation's proportionate interest in oil and gas assets (in percentage)													3.00%	2.00%