Organization	12 Months Ended
Dec. 31, 2018
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, Brazil, North Sea, Asia Pacific and West Africa regions. 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 13). Our Well Intervention segment includes our vessels and equipment used to perform well intervention services primarily in the U.S. Gulf of Mexico, Brazil, the North Sea and West Africa. Our well intervention vessels include the Q4000, the Q5000, the Seawell, the Well Enhancer, and two chartered monohull vessels, the Siem Helix 1 and the Siem Helix 2. We also have a semi-submersible well intervention vessel under completion, the Q7000. Our well intervention equipment includes intervention riser systems (“IRSs”), some of which we provide on a stand-alone basis, and subsea intervention lubricators (“SILs”). Our Robotics segment includes remotely operated vehicles (“ROVs”), trenchers and ROVDrills, which are designed to complement offshore construction and well intervention services, and three ROV support vessels under long-term charter: the Grand Canyon, the Grand Canyon II, and the Grand Canyon III. We also utilize spot vessels as needed. We returned the Deep Cygnus to its owner during the first quarter of 2018. 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 combines our HP I, Q4000 and Q5000 vessels with certain well control equipment that can be deployed to respond to a well control incident in the Gulf of Mexico. On January 16, 2019, we renewed the agreements that provide various operators with access to the HFRS for well control purposes through March 31, 2020. These agreements automatically renew on an annual basis absent proper notice of termination by one of the parties. The HP I has been under contract to the Phoenix field operator since February 2013 and is currently under a fixed fee agreement through at least June 1, 2023. The Production Facilities segment also includes our ownership interest in Independence Hub, LLC (“Independence Hub”) (Note 5). On January 18, 2019, we purchased from Marathon Oil Corporation (“Marathon Oil”) certain operating depths associated with the Droshky Prospect on offshore Gulf of Mexico Green Canyon Block 244, along with several wells and related infrastructure. As part of the transaction, Marathon Oil will pay us certain agreed upon amounts for the required plug and abandonment of the acquired assets, which we can perform as our schedules permit subject to regulatory timelines. There also is a limited amount of production associated with two wells that were acquired as part of the transaction.

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, Brazil, North Sea, Asia Pacific and West Africa regions.

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 13).

Our Well Intervention segment includes our vessels and equipment used to perform well intervention services primarily in the U.S. Gulf of Mexico, Brazil, the North Sea and West Africa. Our well intervention vessels include the Q4000, the Q5000, the Seawell, the Well Enhancer, and two chartered monohull vessels, the Siem Helix 1 and the Siem Helix 2. We also have a semi-submersible well intervention vessel under completion, the Q7000. Our well intervention equipment includes intervention riser systems (“IRSs”), some of which we provide on a stand-alone basis, and subsea intervention lubricators (“SILs”).

Our Robotics segment includes remotely operated vehicles (“ROVs”), trenchers and ROVDrills, which are designed to complement offshore construction and well intervention services, and three ROV support vessels under long-term charter: the Grand Canyon, the Grand Canyon II, and the Grand Canyon III. We also utilize spot vessels as needed. We returned the Deep Cygnus to its owner during the first quarter of 2018.

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 combines our HP I, Q4000 and Q5000 vessels with certain well control equipment that can be deployed to respond to a well control incident in the Gulf of Mexico. On January 16, 2019, we renewed the agreements that provide various operators with access to the HFRS for well control purposes through March 31, 2020. These agreements automatically renew on an annual basis absent proper notice of termination by one of the parties. The HP I has been under contract to the Phoenix field operator since February 2013 and is currently under a fixed fee agreement through at least June 1, 2023. The Production Facilities segment also includes our ownership interest in Independence Hub, LLC (“Independence Hub”) (Note 5). On January 18, 2019, we purchased from Marathon Oil Corporation (“Marathon Oil”) certain operating depths associated with the Droshky Prospect on offshore Gulf of Mexico Green Canyon Block 244, along with several wells and related infrastructure. As part of the transaction, Marathon Oil will pay us certain agreed upon amounts for the required plug and abandonment of the acquired assets, which we can perform as our schedules permit subject to regulatory timelines. There also is a limited amount of production associated with two wells that were acquired as part of the transaction.