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Goodwill and Intangible Assets (Tables) | 12 Months Ended
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Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract] |
Identified Intangible Assets Identified by Segment | Error extracting Word content
Identified Intangible Assets by Major Classification | Error extracting Word content
Goodwill Identified by Segment | Goodwill is identified by segment as follows (in millions):
|  | Wellbore Technologies |  |  | Completion & Production Solutions |  |  | Rig Technologies |  |  | Total |
Balance at December 31, 2016 |  | $ | 2,874 |  |  | $ | 2,058 |  |  | $ | 1,135 |  |  | $ | 6,067 |
Goodwill acquired and adjusted during period |  |  | 37 |  |  |  | 41 |  |  |  | 11 |  |  |  | 89 |
Currency translation adjustments |  |  | 45 |  |  |  | 23 |  |  |  | 3 |  |  |  | 71 |
Balance at December 31, 2017 |  | $ | 2,956 |  |  | $ | 2,122 |  |  | $ | 1,149 |  |  | $ | 6,227 |
Goodwill acquired and adjusted during period |  |  | 64 |  |  |  | (33 | ) |  |  | 71 |  |  |  | 102 |
Currency translation adjustments |  |  | (9 | ) |  |  | (48 | ) |  |  | (8 | ) |  |  | (65 | )
Balance at December 31, 2018 (1) |  | $ | 3,011 |  |  | $ | 2,041 |  |  | $ | 1,212 |  |  | $ | 6,264 |
| (1) | Accumulated goodwill impairment was $2,457 million as of December 31, 2018.

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- Definition Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13854-109267 + Details
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