Long-Term Debt (Schedule of Deferred Financing Costs) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Gross Carrying Amount	$ 36,458	$ 32,872
Accumulated Amortization	(13,059)	(8,575)
Net	23,399	24,297
Term Loan Maturing June 2018 [Member]
Debt Instrument [Line Items]
Gross Carrying Amount	3,638	3,638
Accumulated Amortization	(1,091)	(364)
Net	2,547	3,274
Revolving Credit Facility Maturing June 2018 [Member]
Debt Instrument [Line Items]
Gross Carrying Amount	13,275	13,275
Accumulated Amortization	(3,982)	(1,327)
Net	9,293	11,948
Convertible Senior Notes 2032 [Member]
Debt Instrument [Line Items]
Gross Carrying Amount	3,759	3,759
Accumulated Amortization	(1,763)	(1,148)
Net	1,996	2,611
MARAD Debt [Member]
Debt Instrument [Line Items]
Gross Carrying Amount	12,200	12,200
Accumulated Amortization	(6,223)	(5,736)
Net	5,977	6,464
Nordea Term Loan [Member]
Debt Instrument [Line Items]
Gross Carrying Amount	3,586
Net	$ 3,586

Carrying amount of accumulated amortization of long-term deferred finance costs capitalized at the end of the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 17

-Article 5

+ Details

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

- Details

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

- Definition

Gross amount, as of the balance sheet date, of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings in periods after one year or beyond the normal operating cycle, if longer, over the life of the long-term debt instruments to which such costs pertain.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DeferredFinanceCostsNoncurrentGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Net amount of long-term deferred finance costs capitalized at the end of the reporting period.

+ References

+ Details

Name:	us-gaap_DeferredFinanceCostsNoncurrentNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_LongtermDebtTypeAxis=hlx_ConvertibleSeniorNotes2032Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=hlx_MaradDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=hlx_NordeaTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=hlx_RevolvingCreditFacilityMaturingJune2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=hlx_TermLoanMaturingJune2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: