Document And Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 19, 2021	Jun. 30, 2020
Cover [Abstract]
Entity Registrant Name	HELIX ENERGY SOLUTIONS GROUP, INC.
Entity Central Index Key	0000866829
Entity File Number	001-32936
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Period End Date	Dec. 31, 2020
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	MN
Entity Tax Identification Number	95-3409686
Entity Address, Address Line One	3505 West Sam Houston Parkway North
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77043
City Area Code	281
Local Phone Number	618-0400
Title of 12(b) Security	Common Stock
Trading Symbol	HLX
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 490.8
Entity Common Stock, Shares Outstanding		150,714,706
Documents Incorporated by Reference	Portions of the definitive Proxy Statement for the Annual Meeting of Shareholders to be held on May 19, 2021 are incorporated by reference into Part III hereof.