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Business Segments and Geographic Areas - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017 Business Segment Customer	Dec. 31, 2016 Customer	Dec. 31, 2015
Segment Reporting Information [Line Items]
Number of reportable segments | Segment	3
Number of business units	17
Revenue from rentals, percentage	12.00%	8.00%	7.00%
Customer Concentration Risk [Member] | Revenue [Member]
Segment Reporting Information [Line Items]
Concentration risk, number of customers | Customer	0	0
Concentration risk, percentage	10.00%	10.00%
Wellbore Technologies [Member]
Segment Reporting Information [Line Items]
Number of business units	6
Completion & Production Solutions [Member]
Segment Reporting Information [Line Items]
Number of business units	9
Rig Technologies [Member]
Segment Reporting Information [Line Items]
Number of business units	2

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
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-Topic 275
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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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