Contingencies	3 Months Ended
Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Brazil Internal Investigation Pride International, Inc. (“Pride”), a company we acquired in 2011, commenced drilling operations in Brazil in 2001. In 2008, Pride entered into a drilling services agreement with Petrobras (the "DSA") for ENSCO DS-5, a drillship ordered from Samsung Heavy Industries, a shipyard in South Korea ("SHI"). Beginning in 2006, Pride conducted periodic compliance reviews of its business with Petrobras, and, after the acquisition of Pride, Ensco conducted similar compliance reviews, the most recent of which commenced in early 2015 after media reports were released regarding ongoing investigations of various kickback and bribery schemes in Brazil involving Petrobras. While conducting our compliance review, we became aware of an internal audit report by Petrobras alleging irregularities in relation to the DSA. Upon learning of the Petrobras internal audit report, our Audit Committee appointed independent counsel to lead an investigation into the alleged irregularities. Further, in June and July 2015, we voluntarily contacted the SEC and the DOJ, respectively, to advise them of this matter and our Audit Committee’s investigation. Independent counsel, under the direction of our Audit Committee, has substantially completed its investigation by reviewing and analyzing available documents and correspondence and interviewing current and former employees involved in the DSA negotiations and the negotiation of the ENSCO DS-5 construction contract with SHI (the "DS-5 Construction Contract"). To date, our Audit Committee has found no evidence that Pride or Ensco or any of their current or former employees were aware of or involved in any wrongdoing, and our Audit Committee has found no evidence linking Ensco or Pride to any illegal acts committed by our former marketing consultant, who provided services to Pride and Ensco in connection with the DSA. Independent counsel has continued to provide the SEC and DOJ with updates throughout the investigation, including detailed briefings regarding its investigation and findings. On December 21, 2015, we entered into a one-year tolling agreement with the DOJ. On March 7, 2016, we entered into a one-year tolling agreement with the SEC. Subsequent to initiating our Audit Committee investigation, Brazilian court documents connected to the prosecution of former Petrobras directors and employees as well as certain other third parties, including our former marketing consultant, referenced the alleged irregularities cited in the Petrobras internal audit report. Our former marketing consultant has entered into a plea agreement with the Brazilian authorities. On January 10, 2016, Brazilian authorities filed an indictment against a former Petrobras director. This indictment states that the former Petrobras director received bribes paid out of proceeds from a brokerage agreement entered into for purposes of intermediating a drillship construction contract between SHI and Pride, which we believe to be the DS-5 Construction Contract. The parties to the brokerage agreement were a company affiliated with a person acting on behalf of the former Petrobras director, a company affiliated with our former marketing consultant, and SHI. The indictment alleges that amounts paid by SHI under the brokerage agreement ultimately were used to pay bribes to the former Petrobras director. The indictment does not state that Pride or Ensco or any of their current or former employees were involved in the bribery scheme or had any knowledge of the bribery scheme. On January 4, 2016, we received a notice from Petrobras declaring the DSA void effective immediately. Petrobras’ notice alleges that our former marketing consultant both received and procured the payment to employees of Petrobras of improper payments from SHI and that Pride had knowledge of this activity and assisted in the procurement of and/or facilitated these improper payments. We disagree with Petrobras’ allegations. See "—DSA Dispute" below for additional information. Outside of Petrobras’ allegations, we have not been contacted by any Brazil governmental authority regarding alleged wrongdoing by Pride or Ensco or any of their current or former employees related to this matter. We cannot predict whether any U.S., Brazilian or other governmental authority will seek to investigate Pride's involvement in this matter, or if a proceeding were opened, the scope or ultimate outcome of any such investigation. If the SEC or DOJ determines that violations of the FCPA have occurred, or if any governmental authority determines that we have violated applicable anti-bribery laws, they could seek civil and criminal sanctions, including monetary penalties, against us, as well as changes to our business practices and compliance programs, any of which could have a material adverse effect on our business and financial condition. Our customers, business partners and other stakeholders could seek to take actions adverse to our interests. Further, investigating and resolving such allegations is expensive and could consume significant management time and attention. Although our internal investigation is substantially complete, we cannot predict whether any additional allegations will be made or whether any additional facts relevant to the investigation will be uncovered during the course of the investigation and what impact those allegations and additional facts will have on the timing or conclusions of the investigation. Our Audit Committee will examine any such additional allegations and additional facts and the circumstances surrounding them. DSA Dispute As described above, on January 4, 2016, Petrobras sent a notice to us declaring the DSA void effective immediately, reserving its rights and stating its intention to seek any restitution to which it may be entitled. We disagree with Petrobras’ declaration that the DSA is void. We believe that Petrobras has repudiated the DSA and have therefore accepted the DSA as terminated on April 8, 2016 (the "Termination Date"). At this time, we cannot reasonably determine the validity of Petrobras' claim or the range of our potential exposure, if any. As a result, there can be no assurance as to how this dispute will ultimately be resolved. We did not recognize revenue for amounts owed to us under the DSA from the beginning of the fourth quarter of 2015 through the Termination Date as we concluded that collectability of these amounts was not reasonably assured. Additionally, our receivables from Petrobras related to the DSA from prior to the fourth quarter of 2015 are fully reserved on our condensed consolidated balance sheet as of March 31, 2016. We have initiated arbitration proceedings in the U.K. against Petrobras seeking payment of all amounts owed to us under the DSA, in addition to any other amounts to which we are entitled, and intend to vigorously pursue our claims. We have also initiated separate arbitration proceedings in the U.K. against SHI for any losses we have incurred in connection with the foregoing. There can be no assurance as to how these arbitration proceedings will ultimately be resolved. Asbestos Litigation We and certain subsidiaries have been named as defendants, along with numerous third-party companies as co-defendants, in multi-party lawsuits filed in Mississippi and Louisiana by approximately 47 plaintiffs. The lawsuits seek an unspecified amount of monetary damages on behalf of individuals alleging personal injury or death, primarily under the Jones Act, purportedly resulting from exposure to asbestos on drilling rigs and associated facilities during the 1960s through the 1980s. During 2013, we reached an agreement in principle with 58 plaintiffs to settle lawsuits filed in Mississippi for a nominal amount. A special master reviewed all 58 cases and made an allocation of settlement funds among the parties. The District Court Judge reviewed the allocations and accepted the special master’s recommendations and approved the settlements. The settlement documents for most of the individual plaintiffs have been processed, and the cases have been dismissed. The settlement documents for approximately 13 individual plaintiffs are continuing to be processed. We intend to vigorously defend against the remaining claims and have filed responsive pleadings preserving all defenses and challenges to jurisdiction and venue. However, discovery is still ongoing and, therefore, available information regarding the nature of all pending claims is limited. At present, we cannot reasonably determine how many of the claimants may have valid claims under the Jones Act or estimate a range of potential liability exposure, if any. In addition to the pending cases in Mississippi and Louisiana, we have other asbestos or lung injury claims pending against us in litigation from time to time in other jurisdictions. Although we do not expect final disposition of these asbestos or lung injury lawsuits to have a material adverse effect upon our financial position, operating results or cash flows, there can be no assurances as to the ultimate outcome of the lawsuits. 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 and surety bonds 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 and surety bonds outstanding as of March 31, 2016 totaled $62.5 million and were 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, 2016, we had not been required to make collateral deposits with respect to these agreements.

Contingencies

Brazil Internal Investigation

Pride International, Inc. (“Pride”), a company we acquired in 2011, commenced drilling operations in Brazil in 2001. In 2008, Pride entered into a drilling services agreement with Petrobras (the "DSA") for ENSCO DS-5, a drillship ordered from Samsung Heavy Industries, a shipyard in South Korea ("SHI"). Beginning in 2006, Pride conducted periodic compliance reviews of its business with Petrobras, and, after the acquisition of Pride, Ensco conducted similar compliance reviews, the most recent of which commenced in early 2015 after media reports were released regarding ongoing investigations of various kickback and bribery schemes in Brazil involving Petrobras.

While conducting our compliance review, we became aware of an internal audit report by Petrobras alleging irregularities in relation to the DSA. Upon learning of the Petrobras internal audit report, our Audit Committee appointed independent counsel to lead an investigation into the alleged irregularities. Further, in June and July 2015, we voluntarily contacted the SEC and the DOJ, respectively, to advise them of this matter and our Audit Committee’s investigation. Independent counsel, under the direction of our Audit Committee, has substantially completed its investigation by reviewing and analyzing available documents and correspondence and interviewing current and former employees involved in the DSA negotiations and the negotiation of the ENSCO DS-5 construction contract with SHI (the "DS-5 Construction Contract").

To date, our Audit Committee has found no evidence that Pride or Ensco or any of their current or former employees were aware of or involved in any wrongdoing, and our Audit Committee has found no evidence linking Ensco or Pride to any illegal acts committed by our former marketing consultant, who provided services to Pride and Ensco in connection with the DSA. Independent counsel has continued to provide the SEC and DOJ with updates throughout the investigation, including detailed briefings regarding its investigation and findings. On December 21, 2015, we entered into a one-year tolling agreement with the DOJ. On March 7, 2016, we entered into a one-year tolling agreement with the SEC.

Subsequent to initiating our Audit Committee investigation, Brazilian court documents connected to the prosecution of former Petrobras directors and employees as well as certain other third parties, including our former marketing consultant, referenced the alleged irregularities cited in the Petrobras internal audit report. Our former marketing consultant has entered into a plea agreement with the Brazilian authorities. On January 10, 2016, Brazilian authorities filed an indictment against a former Petrobras director. This indictment states that the former Petrobras director received bribes paid out of proceeds from a brokerage agreement entered into for purposes of intermediating a drillship construction contract between SHI and Pride, which we believe to be the DS-5 Construction Contract. The parties to the brokerage agreement were a company affiliated with a person acting on behalf of the former Petrobras director, a company affiliated with our former marketing consultant, and SHI. The indictment alleges that amounts paid by SHI under the brokerage agreement ultimately were used to pay bribes to the former Petrobras director. The indictment does not state that Pride or Ensco or any of their current or former employees were involved in the bribery scheme or had any knowledge of the bribery scheme.

On January 4, 2016, we received a notice from Petrobras declaring the DSA void effective immediately. Petrobras’ notice alleges that our former marketing consultant both received and procured the payment to employees of Petrobras of improper payments from SHI and that Pride had knowledge of this activity and assisted in the procurement of and/or facilitated these improper payments. We disagree with Petrobras’ allegations. See "—DSA Dispute" below for additional information.

Outside of Petrobras’ allegations, we have not been contacted by any Brazil governmental authority regarding alleged wrongdoing by Pride or Ensco or any of their current or former employees related to this matter. We cannot predict whether any U.S., Brazilian or other governmental authority will seek to investigate Pride's involvement in this matter, or if a proceeding were opened, the scope or ultimate outcome of any such investigation. If the SEC or DOJ determines that violations of the FCPA have occurred, or if any governmental authority determines that we have violated applicable anti-bribery laws, they could seek civil and criminal sanctions, including monetary penalties, against us, as well as changes to our business practices and compliance programs, any of which could have a material adverse effect on our business and financial condition. Our customers, business partners and other stakeholders could seek to take actions adverse to our interests. Further, investigating and resolving such allegations is expensive and could consume significant management time and attention. Although our internal investigation is substantially complete, we cannot predict whether any additional allegations will be made or whether any additional facts relevant to the investigation will be uncovered during the course of the investigation and what impact those allegations and additional facts will have on the timing or conclusions of the investigation. Our Audit Committee will examine any such additional allegations and additional facts and the circumstances surrounding them.

DSA Dispute

As described above, on January 4, 2016, Petrobras sent a notice to us declaring the DSA void effective immediately, reserving its rights and stating its intention to seek any restitution to which it may be entitled. We disagree with Petrobras’ declaration that the DSA is void. We believe that Petrobras has repudiated the DSA and have therefore accepted the DSA as terminated on April 8, 2016 (the "Termination Date"). At this time, we cannot reasonably determine the validity of Petrobras' claim or the range of our potential exposure, if any. As a result, there can be no assurance as to how this dispute will ultimately be resolved.

We did not recognize revenue for amounts owed to us under the DSA from the beginning of the fourth quarter of 2015 through the Termination Date as we concluded that collectability of these amounts was not reasonably assured. Additionally, our receivables from Petrobras related to the DSA from prior to the fourth quarter of 2015 are fully reserved on our condensed consolidated balance sheet as of March 31, 2016. We have initiated arbitration proceedings in the U.K. against Petrobras seeking payment of all amounts owed to us under the DSA, in addition to any other amounts to which we are entitled, and intend to vigorously pursue our claims. We have also initiated separate arbitration proceedings in the U.K. against SHI for any losses we have incurred in connection with the foregoing. There can be no assurance as to how these arbitration proceedings will ultimately be resolved.

Asbestos Litigation

We and certain subsidiaries have been named as defendants, along with numerous third-party companies as co-defendants, in multi-party lawsuits filed in Mississippi and Louisiana by approximately 47 plaintiffs. The lawsuits seek an unspecified amount of monetary damages on behalf of individuals alleging personal injury or death, primarily under the Jones Act, purportedly resulting from exposure to asbestos on drilling rigs and associated facilities during the 1960s through the 1980s.

During 2013, we reached an agreement in principle with 58 plaintiffs to settle lawsuits filed in Mississippi for a nominal amount. A special master reviewed all 58 cases and made an allocation of settlement funds among the parties. The District Court Judge reviewed the allocations and accepted the special master’s recommendations and approved the settlements. The settlement documents for most of the individual plaintiffs have been processed, and the cases have been dismissed. The settlement documents for approximately 13 individual plaintiffs are continuing to be processed.

We intend to vigorously defend against the remaining claims and have filed responsive pleadings preserving all defenses and challenges to jurisdiction and venue. However, discovery is still ongoing and, therefore, available information regarding the nature of all pending claims is limited. At present, we cannot reasonably determine how many of the claimants may have valid claims under the Jones Act or estimate a range of potential liability exposure, if any.

In addition to the pending cases in Mississippi and Louisiana, we have other asbestos or lung injury claims pending against us in litigation from time to time in other jurisdictions. Although we do not expect final disposition of these asbestos or lung injury lawsuits to have a material adverse effect upon our financial position, operating results or cash flows, there can be no assurances as to the ultimate outcome of the lawsuits.

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 and surety bonds 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 and surety bonds outstanding as of March 31, 2016 totaled $62.5 million and were 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, 2016, we had not been required to make collateral deposits with respect to these agreements.