Contingencies	9 Months Ended
Contingencies	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies DSA Dispute On January 4, 2016, Petrobras sent a notice to us declaring the drilling services agreement with Petrobras (the "DSA") for ENSCO DS-5, a drillship ordered from Samsung Heavy Industries, a shipyard in South Korea ("SHI"), void effective immediately, reserving its rights and stating its intention to seek any restitution to which it may be entitled. The previously disclosed arbitral hearing on liability related to the matter was held in March 2018. Prior to the arbitration tribunal issuing its decision, we and Petrobras agreed in August 2018 to a settlement of all claims relating to the DSA. No payments were made by either party in connection with the settlement agreement. The parties agreed to normalize business relations and the settlement agreement provides for our participation in current and future Petrobras tenders on the same basis as all other companies invited to these tenders. No losses were recognized during 2018 with respect to this settlement as all disputed receivables with Petrobras related to the DSA were fully reserved in 2015. In April 2016, we initiated separate arbitration proceedings in the U.K. against SHI for the losses incurred in connection with the foregoing Petrobras arbitration and certain other losses relating to the DSA. In January 2018, the arbitration tribunal for the SHI matter issued an award on liability fully in our favor. The January 2018 arbitration award provides that SHI is liable to us for $10.0 million or damages that we can prove. We submitted our claim for damages to the tribunal, and the arbitral hearing on damages owed to us by SHI took place in the first quarter of 2019. In May 2019, the arbitration tribunal for the SHI matter awarded us $180.0 million in damages. Further, we are entitled to claim interest on this award and costs incurred in connection with this matter. In June 2019, we and SHI filed separate applications with the English High Court to seek leave to appeal the damages awarded. We are awaiting the English High Court decision as to whether it will hear the appeal, which decision is expected in the fourth quarter of 2019. There can be no assurance when we will collect all or any portion of the damages awarded or any related interest or costs. Indonesian Well-Control Event In July 2019, a well being drilled offshore Indonesia by one of our jackup rigs experienced a well-control event requiring the cessation of drilling activities. The operator could seek to terminate the contract under certain circumstances. If this drilling contract were to be terminated for cause, it would result in an approximate $14 million decrease in our backlog as of September 30, 2019. Indonesian authorities have initiated a preliminary investigation into the event and have contacted the customer, us and other parties involved in drilling the well for additional information. We are cooperating with the Indonesian authorities. We cannot predict the scope or ultimate outcome of this preliminary investigation or whether the Indonesian authorities will open a full investigation into our involvement in this matter. If the Indonesian authorities determine that we violated local laws in connection with this matter, we could be subject to penalties including environmental or other liabilities, which may have a material adverse impact on us. Middle East Dispute On July 30, 2019, we received notice that a local partner of legacy Ensco plc in the Middle East filed a lawsuit in the U.K. against the Company alleging it induced the breach of a non-compete provision in an agreement between the local partner and a subsidiary of the Company. The lawsuit includes a claim for an unspecified amount of damages in excess of £100 million and other relief. We strongly disagree and intend to vigorously defend against the lawsuit. We do not have sufficient information at this time to provide a reasonable estimate of potential liability, if any. As a result, there can be no assurance as to how this dispute will ultimately be resolved. Other Matters In addition to the foregoing, we are named defendants or parties in certain other lawsuits, claims or proceedings incidental to our business and are involved from time to time as parties to governmental investigations or proceedings, including matters related to taxation, arising in the ordinary course of business. Although the outcome of such lawsuits or other proceedings cannot be predicted with certainty and the amount of any liability that could arise with respect to such lawsuits or other proceedings cannot be predicted accurately, we do not expect these matters to have a material adverse effect on our financial position, operating results or cash flows. In the ordinary course of business with customers and others, we have entered into letters of credit to guarantee our performance as it relates to our drilling contracts, contract bidding, customs duties, tax appeals and other obligations in various jurisdictions. Letters of credit outstanding as of September 30, 2019 totaled $90.0 million and are issued under facilities provided by various banks and other financial institutions. Obligations under these letters of credit and surety bonds are not normally called, as we typically comply with the underlying performance requirement. As of September 30, 2019, we had not been required to make collateral deposits with respect to these agreements.