XML 45 R29.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Acquisitions and Investments (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2017
Business Combinations [Abstract] |
Summary of Acquisitions | A summary of the acquisitions follows (in millions):
|  | Years Ended December 31, |
|  | 2017 |  |  | 2016 |  |  | 2015 |
Fair value of assets acquired, net of cash acquired |  | $ | 154 |  |  | $ | 357 |  |  | $ | 116 |
Cash paid, net of cash acquired |  |  | (86 | ) |  |  | (230 | ) |  |  | (86 | )
Liabilities assumed, debt issued and noncontrolling interest |  | $ | 68 |  |  | $ | 127 |  |  | $ | 30 |
Excess purchase price over fair value of net assets acquired |  | $ | 89 |  |  | $ | 74 |  |  | $ | 51 |

X
- Definition Summary of Acquisitions. + References No definition available. + Details
Name: | nov_SummaryOfAcquisitionsTableTextBlock
Namespace Prefix: | nov_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_BusinessCombinationsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration