| **Segment Information (Details 5) (USD $)In Millions, unless otherwise specified** | 3 Months Ended | 12 Months Ended |
|------------------------------------------------------------------------------------|----------------|-----------------|
||
| **Consolidated revenue for each group of similar products and services**           |           |            |   |   |   |   |   |   |   |   |   |
| Revenue                                                                            | $ 5,325        | $ 5,355         | $ 5,326 | $ 5,355 | $ 5,387 | $ 5,178 | $ 4,741 | $ 4,525 | $ 21,361 | $ 19,831 | $ 14,414 |
| Completion and Production                                                          |           |            |   |   |   |   |   |   |   |   |   |
| **Consolidated revenue for each group of similar products and services**           |           |            |   |   |   |   |   |   |   |   |   |
| Revenue                                                                            |           |            |   |   |   |   |   |   | 12,949 | 12,469 | 8,548 |
| Drilling and Evaluation                                                            |           |            |   |   |   |   |   |   |   |   |   |
| **Consolidated revenue for each group of similar products and services**           |           |            |   |   |   |   |   |   |   |   |   |
| Revenue                                                                            |           |            |   |   |   |   |   |   | 7,195 | 6,224 | 4,987 |
| Industrial Services and Other                                                      |           |            |   |   |   |   |   |   |   |   |   |
| **Consolidated revenue for each group of similar products and services**           |           |            |   |   |   |   |   |   |   |   |   |
| Revenue                                                                            |           |            |   |   |   |   |   |   | 1,217 | 1,138 | 879 |
| Total                                                                              |           |            |   |   |   |   |   |   |   |   |   |
| **Consolidated revenue for each group of similar products and services**           |           |            |   |   |   |   |   |   |   |   |   |
| Revenue                                                                            |           |            |   |   |   |   |   |   | $ 21,361 | $ 19,831 | $ 14,414 |

| X                                                                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5
+ Details**Name:**us-gaap_SalesRevenueNet**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |