The percentage of service or performance based units awarded based on service and market conditions.

No definition available.

Name:	hlx_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentageBasedOnServiceAndMarketConditions
Namespace Prefix:	hlx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of service or performance based units awarded based on service and performance conditions.

+ References

No definition available.

+ Details

Name:	hlx_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentageBasedOnServiceAndPerformanceConditions
Namespace Prefix:	hlx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of components of service or performance based units awarded based on service and market conditions.

+ References

No definition available.

+ Details

Name:	hlx_ShareBasedCompensationArrangementByShareBasedPaymentAwardComponentsOfEquityAwardsGranted
Namespace Prefix:	hlx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Grant date of share-based payment award.

+ References

No definition available.

+ Details

Name:	hlx_ShareBasedCompensationArrangementByShareBasedPaymentAwardGrantDate
Namespace Prefix:	hlx_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Vesting date of share-based payment award.

+ References

No definition available.

+ Details

Name:	hlx_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingDate
Namespace Prefix:	hlx_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

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

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of vesting of award under share-based payment arrangement.

+ References

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GranteeStatusAxis=hlx_ManagementAndEmployeeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GranteeStatusAxis=srt_DirectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Employee Benefit Plans - Share-Based Awards Granted (Details)						1 Months Ended	9 Months Ended
	Jul. 23, 2021 $ / shares shares	Jul. 01, 2021 $ / shares shares	Apr. 01, 2021 $ / shares shares	Jan. 04, 2021 item $ / shares shares	Jan. 01, 2021 $ / shares shares	Jan. 31, 2021	Sep. 30, 2021 shares
RSUs \| Management and Employee
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Date of Grant					Jan. 01, 2021
Shares/Units					452,381
Grant Date Fair Value Per Share/Unit \| $ / shares					$ 4.20
Vesting Percentage					33.00%
Vesting Period					3 years
Performance Share Units
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting Percentage						200.00%
Percentage based on service and market conditions				50.00%
Percentage based on service and performance conditions				50.00%
Number of components of equity awards granted \| item				2
Performance Share Units \| Management and Employee
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Date of Grant				Jan. 04, 2021
Shares/Units				452,381
Grant Date Fair Value Per Share/Unit \| $ / shares				$ 5.33
Vesting Percentage				100.00%
Vesting Date				Jan. 04, 2024
Restricted Stock
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares/Units							0
Restricted Stock \| Board of Directors
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Date of Grant	Jul. 23, 2021	Jul. 01, 2021	Apr. 01, 2021	Jan. 04, 2021
Shares/Units	14,664	8,403	9,282	14,249
Grant Date Fair Value Per Share/Unit \| $ / shares	$ 4.54	$ 5.71	$ 5.05	$ 4.20
Vesting Percentage	100.00%	100.00%	100.00%	100.00%
Vesting Date	Jul. 23, 2022	Jan. 01, 2023	Jan. 01, 2023	Jan. 01, 2023