Organization	12 Months Ended
Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization Unless the context indicates otherwise, the terms “we,” “us” and “our” in this Annual Report refer collectively to Helix Energy Solutions Group, Inc. and its subsidiaries (“Helix” or the “Company”). We are an international offshore energy services company that provides specialty services to the offshore energy industry, with a focus on well intervention and robotics operations. We provide services primarily in deepwater in the U.S. Gulf of Mexico, North Sea, Asia Pacific and West Africa regions, and in 2017 expanded our operations into Brazil with the commencement of operations of the Siem Helix 1 and Siem Helix 2 vessels for Petróleo Brasileiro S.A. (“Petrobras”). Our Operations We seek to provide services and methodologies that we believe are critical to maximizing production economics. Our “life of field” services are segregated into three reportable business segments: Well Intervention, Robotics and Production Facilities (Note 12). Our Well Intervention segment includes our vessels and equipment used to perform well intervention services primarily in the U.S. Gulf of Mexico, North Sea and Brazil. Our Well Intervention segment also includes intervention riser systems (“IRSs”), some of which we rent out on a stand-alone basis, and subsea intervention lubricators (“SILs”). Our well intervention vessels include the Q4000, the Q5000, the Seawell, the Well Enhancer, and two chartered newbuild monohull vessels, the Siem Helix 1 and the Siem Helix 2. We also have a semi-submersible well intervention vessel under construction, the Q7000. The Siem Helix 1 commenced well intervention operations for Petrobras offshore Brazil in April 2017, and the Siem Helix 2 commenced operations for Petrobras in December 2017. We returned the Skandi Constructor to its owner in March 2017 upon the expiration of the vessel charter. Our Robotics segment includes remotely operated vehicles (“ROVs”), trenchers and ROVDrills designed to complement offshore construction and well intervention services, and currently operates three ROV support vessels under long-term charter, including the Grand Canyon III that went into service for us in May 2017. We also utilize spot vessels as needed. Our vessel charter for the Deep Cygnus was terminated on February 9, 2018, at which time we returned the vessel to its owner. Our Production Facilities segment includes the Helix Producer I (the “HP I”), a ship-shaped dynamically positioned floating production vessel, and the Helix Fast Response System (the “HFRS”), which provides certain operators access to our Q4000 and HP I vessels in the event of a well control incident in the Gulf of Mexico. The HP I has been under contract to the Phoenix field operator since February 2013, currently under a fixed fee agreement through at least June 1, 2023. We are party to an agreement providing various operators with access to the HFRS for well control purposes, which agreement was amended effective February 1, 2017 to extend the term of the agreement by one year to March 31, 2019 and to reduce the retainer fee. The Production Facilities segment also includes our ownership interest in Independence Hub, LLC (“Independence Hub”).

Organization

Unless the context indicates otherwise, the terms “we,” “us” and “our” in this Annual Report refer collectively to Helix Energy Solutions Group, Inc. and its subsidiaries (“Helix” or the “Company”). We are an international offshore energy services company that provides specialty services to the offshore energy industry, with a focus on well intervention and robotics operations. We provide services primarily in deepwater in the U.S. Gulf of Mexico, North Sea, Asia Pacific and West Africa regions, and in 2017 expanded our operations into Brazil with the commencement of operations of the Siem Helix 1 and Siem Helix 2 vessels for Petróleo Brasileiro S.A. (“Petrobras”).

Our Operations

We seek to provide services and methodologies that we believe are critical to maximizing production economics. Our “life of field” services are segregated into three reportable business segments: Well Intervention, Robotics and Production Facilities (Note 12).

Our Well Intervention segment includes our vessels and equipment used to perform well intervention services primarily in the U.S. Gulf of Mexico, North Sea and Brazil. Our Well Intervention segment also includes intervention riser systems (“IRSs”), some of which we rent out on a stand-alone basis, and subsea intervention lubricators (“SILs”). Our well intervention vessels include the Q4000, the Q5000, the Seawell, the Well Enhancer, and two chartered newbuild monohull vessels, the Siem Helix 1 and the Siem Helix 2. We also have a semi-submersible well intervention vessel under construction, the Q7000. The Siem Helix 1 commenced well intervention operations for Petrobras offshore Brazil in April 2017, and the Siem Helix 2 commenced operations for Petrobras in December 2017. We returned the Skandi Constructor to its owner in March 2017 upon the expiration of the vessel charter.

Our Robotics segment includes remotely operated vehicles (“ROVs”), trenchers and ROVDrills designed to complement offshore construction and well intervention services, and currently operates three ROV support vessels under long-term charter, including the Grand Canyon III that went into service for us in May 2017. We also utilize spot vessels as needed. Our vessel charter for the Deep Cygnus was terminated on February 9, 2018, at which time we returned the vessel to its owner.

Our Production Facilities segment includes the Helix Producer I (the “HP I”), a ship-shaped dynamically positioned floating production vessel, and the Helix Fast Response System (the “HFRS”), which provides certain operators access to our Q4000 and HP I vessels in the event of a well control incident in the Gulf of Mexico. The HP I has been under contract to the Phoenix field operator since February 2013, currently under a fixed fee agreement through at least June 1, 2023. We are party to an agreement providing various operators with access to the HFRS for well control purposes, which agreement was amended effective February 1, 2017 to extend the term of the agreement by one year to March 31, 2019 and to reduce the retainer fee. The Production Facilities segment also includes our ownership interest in Independence Hub, LLC (“Independence Hub”).