Contingencies	6 Months Ended
Jun. 30, 2014
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies ENSCO 29 Wreck Removal During 2005, a portion of the ENSCO 29 platform drilling rig was lost over the side of a customer's platform as a result of Hurricane Katrina. In June 2014, we received a letter from an operator demanding that Ensco retrieve the derrick and drawworks from the seabed. Our property insurance policies include coverage for ENSCO 29 wreckage and debris removal costs up to $3.8 million. We also maintain liability insurance policies that provide coverage under certain circumstances for wreckage and debris removal costs in excess of the $3.8 million coverage provided under the property insurance policies. We believe that it is not probable a liability exists with respect to this matter, and no liability has been recorded on our condensed consolidated balance sheet as of June 30, 2014. While we cannot reasonably estimate a range of possible loss at this time, it is possible that removal costs may be in excess of our insurance coverage. Although we do not expect costs associated with the ENSCO 29 wreck removal 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. ENSCO 74 Loss During 2008, ENSCO 74 was lost as a result of Hurricane Ike in the U.S. Gulf of Mexico. The sunken rig hull of ENSCO 74 was located approximately 95 miles from the original drilling location when it was struck by an oil tanker during 2009. Wreck removal operations on the sunken rig hull of ENSCO 74 were completed during 2010. We filed a petition for exoneration or limitation of liability under U.S. admiralty and maritime law during 2009. A number of claimants presented claims in the exoneration/limitation proceedings. We have liability insurance policies that provide coverage for such claims as well as removal of wreckage and debris in excess of the property insurance policy sublimit, subject to a $10.0 million per occurrence deductible for third-party claims and an annual aggregate limit of $490.0 million. The owner of a pipeline filed claims alleging that ENSCO 74 caused the pipeline to rupture during Hurricane Ike and sought damages for the cost of repairs and business interruption in an amount in excess of $26.0 million. During the first quarter of 2014, we reached an agreement with the owner of the pipeline to settle the claims for $9.6 million. Prior to the settlement, we incurred legal fees of $3.6 million for this matter. During the second quarter of 2014, we paid the remaining $6.4 million of our deductible under our liability insurance policy, which was included in accrued liabilities and other on our condensed consolidated balance sheet as of December 31, 2013. The remaining $3.2 million of settlement proceeds was paid by our underwriters under the terms of the related insurance policies. The owner of the oil tanker that struck the hull of ENSCO 74 filed claims seeking monetary damages in excess of $5.0 million for losses incurred when the tanker struck the sunken hull of ENSCO 74. This matter went to trial in June 2014, and the Company won a directed verdict regarding all claims. The plaintiff has the right to appeal the decision. We believe that it is not probable that a liability exists with respect to these claims. We believe all liabilities associated with the ENSCO 74 loss during Hurricane Ike resulted from a single occurrence under the terms of the applicable insurance policies. However, legal counsel for certain liability underwriters have asserted that the liability claims arise from separate occurrences. In the event of multiple occurrences, the self-insured retention is $15.0 million for two occurrences and $1.0 million for each occurrence thereafter. Although we do not expect final disposition of the claims associated with the ENSCO 74 loss 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. 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 100 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. In December 2013, we reached an agreement in principle with 58 of the plaintiffs to settle lawsuits filed in Mississippi for a nominal amount. While we believe the settlement will be approved by the Court, there can be no assurances as to the ultimate outcome. 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 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 June 30, 2014 totaled $248.4 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 June 30, 2014, we had not been required to make collateral deposits with respect to these agreements.

Contingencies

ENSCO 29 Wreck Removal

During 2005, a portion of the ENSCO 29 platform drilling rig was lost over the side of a customer's platform as a result of Hurricane Katrina. In June 2014, we received a letter from an operator demanding that Ensco retrieve the derrick and drawworks from the seabed.

Our property insurance policies include coverage for ENSCO 29 wreckage and debris removal costs up to $3.8 million. We also maintain liability insurance policies that provide coverage under certain circumstances for wreckage and debris removal costs in excess of the $3.8 million coverage provided under the property insurance policies. We believe that it is not probable a liability exists with respect to this matter, and no liability has been recorded on our condensed consolidated balance sheet as of June 30, 2014. While we cannot reasonably estimate a range of possible loss at this time, it is possible that removal costs may be in excess of our insurance coverage. Although we do not expect costs associated with the ENSCO 29 wreck removal 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.

ENSCO 74 Loss

During 2008, ENSCO 74 was lost as a result of Hurricane Ike in the U.S. Gulf of Mexico. The sunken rig hull of ENSCO 74 was located approximately 95 miles from the original drilling location when it was struck by an oil tanker during 2009. Wreck removal operations on the sunken rig hull of ENSCO 74 were completed during 2010.

We filed a petition for exoneration or limitation of liability under U.S. admiralty and maritime law during 2009. A number of claimants presented claims in the exoneration/limitation proceedings. We have liability insurance policies that provide coverage for such claims as well as removal of wreckage and debris in excess of the property insurance policy sublimit, subject to a $10.0 million per occurrence deductible for third-party claims and an annual aggregate limit of $490.0 million.

The owner of a pipeline filed claims alleging that ENSCO 74 caused the pipeline to rupture during Hurricane Ike and sought damages for the cost of repairs and business interruption in an amount in excess of $26.0 million. During the first quarter of 2014, we reached an agreement with the owner of the pipeline to settle the claims for $9.6 million. Prior to the settlement, we incurred legal fees of $3.6 million for this matter. During the second quarter of 2014, we paid the remaining $6.4 million of our deductible under our liability insurance policy, which was included in accrued liabilities and other on our condensed consolidated balance sheet as of December 31, 2013. The remaining $3.2 million of settlement proceeds was paid by our underwriters under the terms of the related insurance policies.

The owner of the oil tanker that struck the hull of ENSCO 74 filed claims seeking monetary damages in excess of $5.0 million for losses incurred when the tanker struck the sunken hull of ENSCO 74. This matter went to trial in June 2014, and the Company won a directed verdict regarding all claims. The plaintiff has the right to appeal the decision. We believe that it is not probable that a liability exists with respect to these claims.

We believe all liabilities associated with the ENSCO 74 loss during Hurricane Ike resulted from a single occurrence under the terms of the applicable insurance policies. However, legal counsel for certain liability underwriters have asserted that the liability claims arise from separate occurrences. In the event of multiple occurrences, the self-insured retention is $15.0 million for two occurrences and $1.0 million for each occurrence thereafter.

Although we do not expect final disposition of the claims associated with the ENSCO 74 loss 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.

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 100 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.

In December 2013, we reached an agreement in principle with 58 of the plaintiffs to settle lawsuits filed in Mississippi for a nominal amount. While we believe the settlement will be approved by the Court, there can be no assurances as to the ultimate outcome.

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 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 June 30, 2014 totaled $248.4 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 June 30, 2014, we had not been required to make collateral deposits with respect to these agreements.