The amount of cash paid on settlement of derivative.

No definition available.

Name:	hlx_DerivativeCashSettlement
Namespace Prefix:	hlx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

+ Details

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994

+ Details

Name:	us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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

- Definition

The net gain (loss) during the reporting period due to ineffectiveness in foreign currency cash flow hedges. Recognized in earnings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (d)(1)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959

+ Details

Name:	us-gaap_GainLossOnForeignCurrencyCashFlowHedgeIneffectiveness
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Derivative Instruments And Hedging Activities (Narrative) (Details) In Millions, unless otherwise specified	12 Months Ended	1 Months Ended
	Dec. 31, 2014 USD ($)	Feb. 28, 2013 Oil And Gas Commodity Contracts [Member] USD ($)	Feb. 28, 2013 Interest Rate Swaps [Member] USD ($)	Sep. 30, 2013 Interest Rate Swaps [Member] USD ($)	Feb. 28, 2013 Grand Canyon I I I [Member] USD ($)	Feb. 28, 2013 Grand Canyon I I I [Member] NOK	Feb. 28, 2013 Grand Canyon I I [Member] USD ($)	Feb. 28, 2013 Grand Canyon I I [Member] NOK	Jan. 31, 2013 Grand Canyon [Member] USD ($)	Jan. 31, 2013 Grand Canyon [Member] NOK
Derivative [Line Items]
Derivative cash settlement		$ 22.5	$ 0.6
Notional amount of derivative				148.1	98.8	595.0	100.4	594.7	104.6	591.3
Loss on foreign currency cash flow hedge ineffectiveness	1.7
Cash flow hedge loss to be reclassified within twelve months	$ 7.8