Business Segment Information - Intercompany Segment Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Net revenues	$ (181,021)	$ (166,823)
Well Intervention
Segment Reporting Information [Line Items]
Net revenues	(140,652)	(122,231)
Robotics
Segment Reporting Information [Line Items]
Net revenues	(35,258)	(39,041)
Intercompany Eliminations
Segment Reporting Information [Line Items]
Net revenues	10,430	9,702
Intercompany Eliminations \| Well Intervention
Segment Reporting Information [Line Items]
Net revenues	3,304	3,225
Intercompany Eliminations \| Robotics
Segment Reporting Information [Line Items]
Net revenues	$ 7,126	$ 6,477

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration