Business Segment and Geographic Information (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Revenue:        
Revenue   $ 23,995 $ 20,620 $ 15,887
Operating income (loss):        
Total operating income (loss)   2,467 1,374 (6,770)
Impairments and other charges $ 265 265 647 3,357 [1]
Impairments and other charges [1]   (265) (647) (3,357)
Interest expense, net of interest income   (554) (593) (639)
Other, net   (99) (99) (216)
Income (loss) from continuing operations before income taxes   1,814 682 (7,625)
Capital expenditures:        
Total capital expenditures   2,026 1,373 798
Depreciation, depletion and amortization:        
Total depreciation, depletion and amortization   1,606 1,556 1,503
Total assets:        
Total assets   25,982 25,085  
Property, Plant and Equipment [Abstract]        
Property, Plant and Equipment, Net   8,961 8,521  
Completion and Production        
Revenue:        
Revenue   15,973 13,077 8,882
Operating income (loss):        
Total operating income (loss)   2,278 1,625 108
Impairments and other charges       2,100
Capital expenditures:        
Total capital expenditures   1,364 1,111 500
Depreciation, depletion and amortization:        
Total depreciation, depletion and amortization   1,058 953 900
Total assets:        
Total assets [2]   13,231 12,276  
Drilling and Evaluation        
Revenue:        
Revenue   8,022 7,543 7,005
Operating income (loss):        
Total operating income (loss)   745 726 801
Impairments and other charges       1,200
Capital expenditures:        
Total capital expenditures   657 261 297
Depreciation, depletion and amortization:        
Total depreciation, depletion and amortization   512 563 569
Total assets:        
Total assets [2]   8,037 7,837  
Corporate and shared assets        
Total assets:        
Total assets [3]   4,714 4,972  
Total operations        
Operating income (loss):        
Total operating income (loss)   3,023 2,351 909
Corporate and other        
Operating income (loss):        
Total operating income (loss) [4]   (291) (330) (4,322)
Impairments and other charges       10
Capital expenditures:        
Total capital expenditures   5 1 1
Depreciation, depletion and amortization:        
Total depreciation, depletion and amortization   36 40 34
VENEZUELA        
Operating income (loss):        
Impairments and other charges [1]     (647)  
North America [Member]        
Revenue:        
Revenue   14,431 11,564 6,770
Property, Plant and Equipment [Abstract]        
Property, Plant and Equipment, Net   5,672 4,922  
Latin America [Member]        
Revenue:        
Revenue   2,065 2,116 1,860
Property, Plant and Equipment [Abstract]        
Property, Plant and Equipment, Net   974 945  
Europe/Africa/CIS [Member]        
Revenue:        
Revenue   2,945 2,781 2,993
Property, Plant and Equipment [Abstract]        
Property, Plant and Equipment, Net   938 1,098  
Middle East/Asia [Member]        
Revenue:        
Revenue   4,554 4,159 $ 4,264
Property, Plant and Equipment [Abstract]        
Property, Plant and Equipment, Net   $ 1,377 $ 1,556  
[1] Impairments and other charges are as follows:
-For the year ended December 31, 2018, the aggregate charge of $265 million represents a write-down of all of our remaining investment in Venezuela, consisting of receivables, fixed assets, inventory and other assets and liabilities.
-For the year ended December 31, 2017, the aggregate charge of $647 million represents a fair market value adjustment on our existing promissory note with our primary customer in Venezuela and a full reserve against our other accounts receivable with this customer.
-For the year ended December 31, 2016, the aggregate charge of $3.4 billion consisted of fixed asset impairments and write-offs, inventory write-downs, impairments of intangible assets, severance costs, country and facility closures, and other charges related to the energy downturn. This included $2.1 billion attributable to Completion and Production, $1.2 billion attributable to Drilling and Evaluation and $10 million attributable to Corporate and other.
[2] Assets associated with specific segments primarily include receivables, inventories, certain identified property, plant and equipment (including field service equipment), equity in and advances to related companies and goodwill.
[3] Corporate and other shared assets primarily include cash and equivalents and deferred tax assets.
[4] Includes certain expenses not attributable to a particular business segment, such as costs related to support functions and corporate executives, and also includes amortization expense associated with intangible assets recorded as a result of acquisitions. Also includes merger-related costs and a termination fee during the year ended December 31, 2016.