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Summary of Significant Accounting Policies - Goodwill Identified by Segment (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Goodwill [Line Items] |  |
Goodwill, Beginning Balance | $ 6,067 | $ 6,980
Goodwill acquired and adjusted during period | 89 | 74
Impairment |  | (972)
Currency translation adjustments | 71 | (15)
Goodwill, Ending Balance | 6,227 | 6,067
Wellbore Technologies [Member] |  |
Goodwill [Line Items] |  |
Goodwill, Beginning Balance | 2,874 | 2,874
Goodwill acquired and adjusted during period | 37 | 4
Currency translation adjustments | 45 | (4)
Goodwill, Ending Balance | 2,956 | 2,874
Completion & Production Solutions [Member] |  |
Goodwill [Line Items] |  |
Goodwill, Beginning Balance | 2,058 | 1,997
Goodwill acquired and adjusted during period | 41 | 70
Currency translation adjustments | 23 | (9)
Goodwill, Ending Balance | 2,122 | 2,058
Rig Technologies [Member] |  |
Goodwill [Line Items] |  |
Goodwill, Beginning Balance | 1,135 | 2,109
Goodwill acquired and adjusted during period | 11 |
Impairment |  | (972)
Currency translation adjustments | 3 | (2)
Goodwill, Ending Balance | $ 1,149 | $ 1,135

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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 + Details
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