Business Segment and Geographic Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue:
Total revenue	$ 28,503	$ 24,829	$ 17,973
Operating income:
Total operating income	4,159	4,737	3,009
Interest expense, net of interest income	(298)	(263)	(297)
Other, net	(39)	(25)	(57)
Income from continuing operations before income taxes	3,822	4,449	2,655
Capital expenditures:
Total capital expenditures	3,566	2,953	2,069
Depreciation, depletion, and amortization:
Total depreciation, depletion and amortization	1,628	1,359	1,119
Revenue:
United States	15,057	13,548	8,209
Other countries	13,446	11,281	9,764
Total revenue	28,503	24,829	17,973
Long-lived assets:
United States	7,219	6,602
Other countries	6,633	5,189
Long-lived assets	13,852	11,791
Total assets:
Total assets	27,410	23,677
Completion and Production
Revenue:
Total revenue	17,380	15,143	9,997
Operating income:
Total operating income	3,144	3,733	2,032
Capital expenditures:
Total capital expenditures	2,177	1,669	1,010
Depreciation, depletion, and amortization:
Total depreciation, depletion and amortization	843	680	537
Revenue:
Total revenue	17,380	15,143	9,997
Total assets:
Total assets	13,313	10,953
Drilling and Evaluation
Revenue:
Total revenue	11,123	9,686	7,976
Operating income:
Total operating income	1,675	1,403	1,213
Capital expenditures:
Total capital expenditures	1,318	1,231	1,058
Depreciation, depletion, and amortization:
Total depreciation, depletion and amortization	783	676	578
Revenue:
Total revenue	11,123	9,686	7,976
Total assets:
Total assets	9,290	8,212
Shared assets
Total assets:
Total assets	1,376	1,249
Total operations
Operating income:
Total operating income	4,819	5,136	3,245
Corporate and other
Operating income:
Total operating income	(660)	(399)	(236)
Capital expenditures:
Total capital expenditures	71	53	1
Depreciation, depletion, and amortization:
Total depreciation, depletion and amortization	2	3	4
Total assets:
Total assets	$ 3,431	$ 3,263