XML 48 R37.htm IDEA: XBRL DOCUMENT
v3.21.2

Company Overview (Details) | 1 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Jun. 30, 2021 | Sep. 30, 2021 item segment | Mar. 31, 2021
Segment Reporting Information [Line Items] |  |  |
Number of reportable segments | segment |  | 3 |
Well Intervention |  |  |
Segment Reporting Information [Line Items] |  |  |
Number of long-term chartered vessels |  | 2 |
Robotics |  |  |
Segment Reporting Information [Line Items] |  |  |
Number of long-term chartered vessels |  | 2 |
STL |  |  |
Segment Reporting Information [Line Items] |  |  |
Percentage of ownership interest |  |  | 70.00%
Controlling interest acquired, ownership percentage | 30.00% |  |

X
- Definition The percentage of ownership acquired of common stock or equity participation in the investee accounted for under the equity method of accounting. + References No definition available. + Details
Name: | hlx_EquityMethodInvestmentOwnershipPercentageAcquired
Namespace Prefix: | hlx_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number Of Long Term Chartered Vessels + References No definition available. + Details
Name: | hlx_NumberOfLongTermCharteredVessels
Namespace Prefix: | hlx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition 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. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8672-108599 + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=hlx_WellInterventionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=hlx_RoboticsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=hlx_STLMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |