Commitments and Contingencies	6 Months Ended
Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 15— Commitments and Contingencies Transocean Ltd. In January 2017, a subsidiary of Transocean Ltd. (“Transocean”) filed suit against us and certain of our subsidiaries for patent infringement in a Texas federal court. The suit claims that five of our newbuild rigs that operated in the U.S. Gulf of Mexico violated Transocean patents relating to what is generally referred to as dual-activity drilling. We were aware of the patents, which are now expired in the United States and most other countries, when we constructed the rigs. While there is inherent risk in litigation, we do not believe that our rigs infringe the Transocean patents. The lawsuit is currently in the discovery phase and we intend to defend ourselves vigorously against this claim. Department of Justice settlement. In December 2014, one of our subsidiaries reached a settlement with the U.S. Department of Justice (“DOJ”) regarding our former drillship, the Noble Discoverer, and the Kulluk, a rig we were providing contract labor services for, in respect of violations of applicable law discovered in connection with a 2012 Coast Guard inspection in Alaska and our own subsequent internal investigation. Under the terms of the agreement, the subsidiary paid $8.2 million in fines and $4.0 million in community service payments and was placed on probation for four years, with the right to petition the court for early dismissal of probation after three years. The subsidiary's motion to early terminate the plea agreement was granted and the plea agreement was terminated effective as of March 1, 2018. We also implemented a comprehensive environmental compliance plan in connection with the settlement. Brazil commercial agent. We previously used a commercial agent in Brazil in connection with our Petróleo Brasileiro S.A. (“Petrobras”) drilling contracts. This agent represented a number of different companies in Brazil over many years, including several offshore drilling contractors. In November 2015, this agent pled guilty in Brazil in connection with the award of a drilling contract to a competitor and implicated a Petrobras official as part of a wider investigation of Petrobras’ business practices. Following news reports relating to the agent’s involvement in the Brazil investigation in connection with his activities with other companies, we conducted a review, which was substantially completed in 2017, of our relationship with the agent and with Petrobras. We have been in contact with the SEC, the Brazilian federal prosecutor’s office and the U.S Department of Justice about this matter. We have cooperated with these agencies and they are aware of our internal review. To our knowledge, neither the agent, nor the government authorities investigating the matter, has alleged that the agent or Noble acted improperly in connection with our contracts with Petrobras. Paragon Offshore. On August 1, 2014, Noble-UK completed the separation and spin-off of a majority of its standard specification offshore drilling business (the “Spin-off”) through a pro rata distribution of all of the ordinary shares of its wholly-owned subsidiary, Paragon Offshore, to the holders of Noble’s ordinary shares. In February 2016, Paragon Offshore sought approval of a pre-negotiated plan of reorganization (the “Prior Plan”) by filing for voluntary relief under Chapter 11 of the United States Bankruptcy Code. As part of the Prior Plan, we entered into a settlement agreement with Paragon Offshore (the “Settlement Agreement”). The Prior Plan was rejected by the bankruptcy court in October 2016. In April 2017, Paragon Offshore filed a revised plan of reorganization (the “New Plan”) in its bankruptcy proceeding. Under the New Plan, Paragon Offshore no longer needed the Mexican tax bonding that Noble-UK was to provide under the Settlement Agreement. Consequently, Paragon Offshore abandoned the Settlement Agreement as part of the New Plan, and the Settlement Agreement was terminated at the time of the filing of the New Plan. On May 2, 2017, Paragon Offshore announced that it had reached an agreement in principle with both its secured and unsecured creditors to revise the New Plan to, among other things, create and fund a $10.0 million litigation trust to pursue litigation against us. On June 7, 2017, the revised New Plan was approved by the bankruptcy court, and Paragon Offshore emerged from bankruptcy on July 18, 2017. On December 15, 2017, the litigation trust filed claims relating to the Spin-off against us and certain of our current and former officers and directors in the Delaware bankruptcy court that heard Paragon Offshore’s bankruptcy. The complaint alleges claims of alleged actual and constructive fraudulent conveyance, unjust enrichment and recharacterization of intercompany notes as equity claims against Noble and claims of breach of fiduciary duty and aiding and abetting breach of fiduciary duty against the officer and director defendants. We have requested that the court dismiss the claims of breach of fiduciary duty, aiding and abetting breach of fiduciary duty and unjust enrichment, and require such claims to be arbitrated under the Master Separation Agreement (the “MSA”) entered into between Noble and Paragon Offshore at the time of the Spin-off, as well as stay the other proceedings during the pendency of the arbitration. The court has stayed discovery pending its ruling. The court has approved a litigation schedule, which, if our request for arbitration is denied and the court proceedings resume in the third quarter of 2018, would conclude all pre-trial motions and other activity by approximately the end of the third quarter or the beginning of the fourth quarter of 2019. We believe that Paragon Offshore, at the time of the Spin-off, was properly funded, solvent and had appropriate liquidity and that the claims brought by the litigation trust are without merit. We intend to defend ourselves vigorously. However, there is inherent risk and substantial expense in litigation, and the amount of damages the plaintiff is seeking is substantial. If any of the litigation trust’s claims are successful, or if we elect to settle any claims (in part to reduce or eliminate the ongoing cost of defending the litigation and eliminate any risk of a larger judgment against us), any damages or other amounts we would be required to or agree to pay could have a material adverse effect on our business, financial condition and results of operations. We may also establish reserves on our financial statements in advance of the conclusion of the litigation. Such reserves may be material and could have a material adverse effect on our financial condition and results of operations. Prior to the completion of the Spin-off, Noble-UK and Paragon Offshore entered into a series of agreements to effect the separation and Spin-off and govern the relationship between the parties after the Spin-off (the “Separation Agreements”), including the MSA and a Tax Sharing Agreement (the “TSA”). As part of its final bankruptcy plan, Paragon Offshore rejected the Separation Agreements. Accordingly, the indemnity obligations that Paragon Offshore potentially would have owed us under the Separation Agreements have now terminated, including indemnities arising under the MSA and the TSA in respect of obligations related to Paragon Offshore’s business that were incurred through Noble-retained entities prior to the Spin-off. Likewise, any potential indemnity obligations that we would have owed Paragon Offshore under the Separation Agreements, including those under the MSA and the TSA in respect of Noble-UK’s business that was conducted prior to the Spin-off through Paragon Offshore-retained entities, are now also extinguished. In the absence of the Separation Agreements, liabilities relating to the respective parties will be borne by the owner of the legal entity or asset at issue and neither party will look to an allocation based on the historic relationship of an entity or asset to one of the party’s business, as had been the case under the Separation Agreements. The rejection and ultimate termination of the indemnity and related obligations under the Separation Agreements resulted in a number of accounting charges and benefits during the year ended December 31, 2017, and such termination may continue to affect us in the future as liabilities arise for which we would have been indemnified by Paragon Offshore or would have had to indemnify Paragon Offshore. We do not expect that, overall, the rejection of the Separation Agreements by Paragon Offshore will have a material adverse effect on our financial condition or liquidity. However, any loss we experience with respect to which we would have been able to secure indemnification from Paragon Offshore under one or more of the Separation Agreements could have an adverse impact on our results of operations in any period, which impact may be material depending on our results of operations during this down-cycle. Tax matters. During 2014, the Internal Revenue Service (“IRS”) began its examination of our tax reporting in the U.S. for the taxable years ended December 31, 2010 and 2011. The IRS examination team has completed its examination of our 2010 and 2011 U.S. tax returns and proposed adjustments and deficiencies with respect to certain items that were reported by us for the 2010 and 2011 tax year. On December 19, 2016, we received the Revenue Agent Report (“RAR”) from the IRS. We believe that we have accurately reported all amounts in our tax returns, and have submitted administrative protests with the IRS Office of Appeals contesting the examination team’s proposed adjustments. We intend to vigorously defend our reported positions, and believe the ultimate resolution of the adjustments proposed by the IRS examination team will not have a material adverse effect on our condensed consolidated financial statements. During the third quarter of 2017, the IRS initiated its examination of our 2012, 2013, 2014 and 2015 tax returns. Audit claims of approximately $48.6 million attributable to income and other business taxes have been assessed against Noble entities in Mexico. We intend to vigorously defend our reported positions, and believe the ultimate resolution of the audit claims will not have a material adverse effect on our Condensed Consolidated Financial Statements. We operate in a number of countries throughout the world and our tax returns filed in those jurisdictions are subject to review and examination by tax authorities within those jurisdictions. We recognize uncertain tax positions that we believe have a greater than 50 percent likelihood of being sustained. We cannot predict or provide assurance as to the ultimate outcome of any existing or future assessments. Other contingencies. We have entered into agreements with certain of our executive officers, as well as certain other employees. These agreements become effective upon a change of control of Noble-UK (within the meaning set forth in the agreements) or a termination of employment in connection with or in anticipation of a change of control, and remain effective for three years thereafter. These agreements provide for compensation and certain other benefits under such circumstances. We are a defendant in certain claims and litigation arising out of operations in the ordinary course of business, including personal injury claims, the resolution of which, in the opinion of management, will not be material to our financial position, results of operations or cash flows. There is inherent risk in any litigation or dispute and no assurance can be given as to the outcome of these claims.

Note 15— Commitments and Contingencies

Transocean Ltd.

In January 2017, a subsidiary of Transocean Ltd. (“Transocean”) filed suit against us and certain of our subsidiaries for patent infringement in a Texas federal court. The suit claims that five of our newbuild rigs that operated in the U.S. Gulf of Mexico violated Transocean patents relating to what is generally referred to as dual-activity drilling. We were aware of the patents, which are now expired in the United States and most other countries, when we constructed the rigs. While there is inherent risk in litigation, we do not believe that our rigs infringe the Transocean patents. The lawsuit is currently in the discovery phase and we intend to defend ourselves vigorously against this claim.

Department of Justice settlement.

In December 2014, one of our subsidiaries reached a settlement with the U.S. Department of Justice (“DOJ”) regarding our former drillship, the Noble Discoverer, and the Kulluk, a rig we were providing contract labor services for, in respect of violations of applicable law discovered in connection with a 2012 Coast Guard inspection in Alaska and our own subsequent internal investigation. Under the terms of the agreement, the subsidiary paid $8.2 million in fines and $4.0 million in community service payments and was placed on probation for four years, with the right to petition the court for early dismissal of probation after three years. The subsidiary's motion to early terminate the plea agreement was granted and the plea agreement was terminated effective as of March 1, 2018. We also implemented a comprehensive environmental compliance plan in connection with the settlement.

Brazil commercial agent.

We previously used a commercial agent in Brazil in connection with our Petróleo Brasileiro S.A. (“Petrobras”) drilling contracts. This agent represented a number of different companies in Brazil over many years, including several offshore drilling contractors. In November 2015, this agent pled guilty in Brazil in connection with the award of a drilling contract to a competitor and implicated a Petrobras official as part of a wider investigation of Petrobras’ business practices. Following news reports relating to the agent’s involvement in the Brazil investigation in connection with his activities with other companies, we conducted a review, which was substantially completed in 2017, of our relationship with the agent and with Petrobras. We have been in contact with the SEC, the Brazilian federal prosecutor’s office and the U.S Department of Justice about this matter. We have cooperated with these agencies and they are aware of our internal review. To our knowledge, neither the agent, nor the government authorities investigating the matter, has alleged that the agent or Noble acted improperly in connection with our contracts with Petrobras.

Paragon Offshore.

On August 1, 2014, Noble-UK completed the separation and spin-off of a majority of its standard specification offshore drilling business (the “Spin-off”) through a pro rata distribution of all of the ordinary shares of its wholly-owned subsidiary, Paragon Offshore, to the holders of Noble’s ordinary shares. In February 2016, Paragon Offshore sought approval of a pre-negotiated plan of reorganization (the “Prior Plan”) by filing for voluntary relief under Chapter 11 of the United States Bankruptcy Code. As part of the Prior Plan, we entered into a settlement agreement with Paragon Offshore (the “Settlement Agreement”). The Prior Plan was rejected by the bankruptcy court in October 2016.

In April 2017, Paragon Offshore filed a revised plan of reorganization (the “New Plan”) in its bankruptcy proceeding. Under the New Plan, Paragon Offshore no longer needed the Mexican tax bonding that Noble-UK was to provide under the Settlement Agreement. Consequently, Paragon Offshore abandoned the Settlement Agreement as part of the New Plan, and the Settlement Agreement was terminated at the time of the filing of the New Plan. On May 2, 2017, Paragon Offshore announced that it had reached an agreement in principle with both its secured and unsecured creditors to revise the New Plan to, among other things, create and fund a $10.0 million litigation trust to pursue litigation against us. On June 7, 2017, the revised New Plan was approved by the bankruptcy court, and Paragon Offshore emerged from bankruptcy on July 18, 2017.

On December 15, 2017, the litigation trust filed claims relating to the Spin-off against us and certain of our current and former officers and directors in the Delaware bankruptcy court that heard Paragon Offshore’s bankruptcy. The complaint alleges claims of alleged actual and constructive fraudulent conveyance, unjust enrichment and recharacterization of intercompany notes as equity claims against Noble and claims of breach of fiduciary duty and aiding and abetting breach of fiduciary duty against the officer and director defendants. We have requested that the court dismiss the claims of breach of fiduciary duty, aiding and abetting breach of fiduciary duty and unjust enrichment, and require such claims to be arbitrated under the Master Separation Agreement (the “MSA”) entered into between Noble and Paragon Offshore at the time of the Spin-off, as well as stay the other proceedings during the pendency of the arbitration. The court has stayed discovery pending its ruling. The court has approved a litigation schedule, which, if our request for arbitration is denied and the court proceedings resume in the third quarter of 2018, would conclude all pre-trial motions and other activity by approximately the end of the third quarter or the beginning of the fourth quarter of 2019.

We believe that Paragon Offshore, at the time of the Spin-off, was properly funded, solvent and had appropriate liquidity and that the claims brought by the litigation trust are without merit. We intend to defend ourselves vigorously. However, there is inherent risk and substantial expense in litigation, and the amount of damages the plaintiff is seeking is substantial. If any of the litigation trust’s claims are successful, or if we elect to settle any claims (in part to reduce or eliminate the ongoing cost of defending the litigation and eliminate any risk of a larger judgment against us), any damages or other amounts we would be required to or agree to pay could have a material adverse effect on our business, financial condition and results of operations. We may also establish reserves on our financial statements in advance of the conclusion of the litigation. Such reserves may be material and could have a material adverse effect on our financial condition and results of operations.

Prior to the completion of the Spin-off, Noble-UK and Paragon Offshore entered into a series of agreements to effect the separation and Spin-off and govern the relationship between the parties after the Spin-off (the “Separation Agreements”), including the MSA and a Tax Sharing Agreement (the “TSA”).

As part of its final bankruptcy plan, Paragon Offshore rejected the Separation Agreements. Accordingly, the indemnity obligations that Paragon Offshore potentially would have owed us under the Separation Agreements have now terminated, including indemnities arising under the MSA and the TSA in respect of obligations related to Paragon Offshore’s business that were incurred through Noble-retained entities prior to the Spin-off. Likewise, any potential indemnity obligations that we would have owed Paragon Offshore under the Separation Agreements, including those under the MSA and the TSA in respect of Noble-UK’s business that was conducted prior to the Spin-off through Paragon Offshore-retained entities, are now also extinguished. In the absence of the Separation Agreements, liabilities relating to the respective parties will be borne by the owner of the legal entity or asset at issue and neither party will look to an allocation based on the historic relationship of an entity or asset to one of the party’s business, as had been the case under the Separation Agreements.

The rejection and ultimate termination of the indemnity and related obligations under the Separation Agreements resulted in a number of accounting charges and benefits during the year ended December 31, 2017, and such termination may continue to affect us in the future as liabilities arise for which we would have been indemnified by Paragon Offshore or would have had to indemnify Paragon Offshore. We do not expect that, overall, the rejection of the Separation Agreements by Paragon Offshore will have a material adverse effect on our financial condition or liquidity. However, any loss we experience with respect to which we would have been able to secure indemnification from Paragon Offshore under one or more of the Separation Agreements could have an adverse impact on our results of operations in any period, which impact may be material depending on our results of operations during this down-cycle.

Tax matters.

During 2014, the Internal Revenue Service (“IRS”) began its examination of our tax reporting in the U.S. for the taxable years ended December 31, 2010 and 2011. The IRS examination team has completed its examination of our 2010 and 2011 U.S. tax returns and proposed adjustments and deficiencies with respect to certain items that were reported by us for the 2010 and 2011 tax year. On December 19, 2016, we received the Revenue Agent Report (“RAR”) from the IRS. We believe that we have accurately reported all amounts in our tax returns, and have submitted administrative protests with the IRS Office of Appeals contesting the examination team’s proposed adjustments. We intend to vigorously defend our reported positions, and believe the ultimate resolution of the adjustments proposed by the IRS examination team will not have a material adverse effect on our condensed consolidated financial statements. During the third quarter of 2017, the IRS initiated its examination of our 2012, 2013, 2014 and 2015 tax returns.

Audit claims of approximately $48.6 million attributable to income and other business taxes have been assessed against Noble entities in Mexico. We intend to vigorously defend our reported positions, and believe the ultimate resolution of the audit claims will not have a material adverse effect on our Condensed Consolidated Financial Statements.

We operate in a number of countries throughout the world and our tax returns filed in those jurisdictions are subject to review and examination by tax authorities within those jurisdictions. We recognize uncertain tax positions that we believe have a greater than 50 percent likelihood of being sustained. We cannot predict or provide assurance as to the ultimate outcome of any existing or future assessments.

Other contingencies.

We have entered into agreements with certain of our executive officers, as well as certain other employees. These agreements become effective upon a change of control of Noble-UK (within the meaning set forth in the agreements) or a termination of employment in connection with or in anticipation of a change of control, and remain effective for three years thereafter. These agreements provide for compensation and certain other benefits under such circumstances.

We are a defendant in certain claims and litigation arising out of operations in the ordinary course of business, including personal injury claims, the resolution of which, in the opinion of management, will not be material to our financial position, results of operations or cash flows. There is inherent risk in any litigation or dispute and no assurance can be given as to the outcome of these claims.