Contingencies	3 Months Ended
Mar. 31, 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 November 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. SHI subsequently filed a statement of defense disputing our claim. In January 2018, the arbitration tribunal for the SHI matter issued an award on liability fully in our favor. In August 2018, the tribunal awarded us approximately $2.8 million in costs and legal fees incurred to date, plus interest, which was collected during the fourth quarter of 2018. 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. We are awaiting the result of the tribunal’s decision, and we are unable to estimate the ultimate outcome of recovery for damages at this time. 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 March 31, 2019 totaled $128.0 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 March 31, 2019, we had not been required to make collateral deposits with respect to these agreements.

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 November 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. SHI subsequently filed a statement of defense disputing our claim. In January 2018, the arbitration tribunal for the SHI matter issued an award on liability fully in our favor. In August 2018, the tribunal awarded us approximately $2.8 million in costs and legal fees incurred to date, plus interest, which was collected during the fourth quarter of 2018.

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. We are awaiting the result of the tribunal’s decision, and we are unable to estimate the ultimate outcome of recovery for damages at this time.

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 March 31, 2019 totaled $128.0 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 March 31, 2019, we had not been required to make collateral deposits with respect to these agreements.