Earnings Per Share - Shares Included in Diluted Calculations Assuming Earnings (Details) - shares shares in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Earnings Per Share
Diluted shares (as reported)	148,515	155,024	150,539	155,072
Share-based awards	742
Total	149,257

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU) including nonvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents.

No definition available.

+ Details

Name:	hlx_WeightedAverageNumberOfSharesOutstandingIncludingIncrementalSharesDiluted
Namespace Prefix:	hlx_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap_EarningsPerShareAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents nonvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid). Basic and dilutive earnings per share are generally disclosed for such shares using the two-class method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 68B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-68B

+ Details

Name:	us-gaap_IncrementalCommonSharesAttributableToParticipatingNonvestedSharesWithNonForfeitableDividendRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482662/260-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 16
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-16

+ Details

Name:	us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration