Long-Term Debt - Credit Agreement (Details) - ABL Facility Maturing September 2026 $ in Millions	9 Months Ended
Sep. 30, 2022 USD ($)
Debt Instrument [Line Items]
Borrowing capacity	$ 100.0
Maturity date	Sep. 30, 2026
Springing maturity period	91 days
Outstanding principal amount with a springing maturity	$ 50.0
Additional commitments (up to)	50.0
Sub-limit for the issuance of letters of credit	10.0
Borrowings under ABL Facility	0.0
Available borrowing capacity	81.8
Letters of credit issued	2.2
Pro Forma
Debt Instrument [Line Items]
Available borrowing capacity	$ 20.0
Available borrowing capacity (as a percent of borrowing base)	10.00%
Permitted debt for the deferred purchase price of property	$ 50.0
Availability of the borrowing base to satisfy and maintain fixed charge ratio	$ 10.0
Period prior to maturity to maintain a pro forma minimum excess availability	91 days
Minimum
Debt Instrument [Line Items]
Commitment fee percentage	0.375%
Fixed charge coverage ratio	1.0
Maximum
Debt Instrument [Line Items]
Commitment fee percentage	0.50%
United States
Debt Instrument [Line Items]
Borrowing capacity	$ 65.0
United States \| SOFR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	1.50%
United States \| SOFR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	2.00%
United States \| Base Rate \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	0.50%
United States \| Base Rate \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	1.00%
United Kingdom
Debt Instrument [Line Items]
Borrowing capacity	$ 35.0
United Kingdom \| SOFR
Debt Instrument [Line Items]
Adjustment on variable rate (as a percent)	0.10%
United Kingdom \| SOFR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	1.50%
United Kingdom \| SOFR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	2.00%
United Kingdom \| SONIA \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	1.50%
United Kingdom \| SONIA \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	2.00%

Percentage points adjusted to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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- Definition

Represents the fixed charge coverage ratio.

+ References

No definition available.

+ Details

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- Definition

Represents the sub-limit of for the issuance of letters of credit under the line of credit facility.

+ References

No definition available.

+ Details

Name:	hlx_LineOfCreditFacilityLettersOfCreditSublimit
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the period prior to the maturity of outstanding debt to maintain a pro forma minimum excess availability.

+ References

No definition available.

+ Details

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- Definition

Represents the permitted debt for the deferred purchase price of property under the credit facility.

+ References

No definition available.

+ Details

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- Definition

Percentage of borrowing capacity currently available under the credit facility (current borrowing capacity divided by the amount of borrowing base).

+ References

No definition available.

+ Details

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- Definition

Represents the springing maturity period prior to the maturity of outstanding debt with outstanding borrowings of $50 million.

+ References

No definition available.

+ Details

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- Definition

Represents the threshold amount for outstanding principal with springing maturity.

+ References

No definition available.

+ Details

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Balance Type:	credit
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- Definition

Represents the amount of the borrowing base available to satisfy and maintain fixed charge ratio.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Maximum commitment increase permitted by ABL Facility.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- 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.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

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Period Type:	duration

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