Commitments and Contingencies	3 Months Ended
Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies In January 2017, a subsidiary of Transocean Ltd. 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 when we constructed the rigs, and we do not believe that our rigs infringe the Transocean patents, which are now expired. We intend to defend ourselves vigorously against this claim. 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 pled guilty to oil record book, ballast record and required hazardous condition reporting violations with respect to the Noble Discoverer and an oil record book violation with respect to the Kulluk. The subsidiary paid $8.2 million in fines and $4 million in community service payments and was placed on probation for four years, provided that we may petition the court for early dismissal of probation after three years. If, during the term of probation, the subsidiary fails to adhere to the terms of the plea agreement, the DOJ may withdraw from the plea agreement and would be free to prosecute the subsidiary on all charges arising out of its investigation, including any charges dismissed pursuant to the terms of the plea agreement, as well as potentially other charges. We also implemented a comprehensive environmental compliance plan in connection with the settlement. We have used a commercial agent in Brazil in connection with our Petróleo Brasileiro S.A. (“Petrobras”) drilling contracts. We understand that this agent has 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 is now substantially complete, of our relationship with the agent and with Petrobras. We are in contact with the SEC, the Brazilian federal prosecutor’s office and the DOJ about this matter. We are cooperating 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. We are from time to time a party to various lawsuits that are incidental to our operations in which the claimants seek an unspecified amount of monetary damages for personal injury, including injuries purportedly resulting from exposure to asbestos on drilling rigs and associated facilities. At March 31, 2017, there were 43 asbestos related lawsuits in which we are one of many defendants. These lawsuits have been filed in the United States in the states of Louisiana and Mississippi. We intend to vigorously defend against the litigation. We do not believe the ultimate resolution of these matters will have a material adverse effect on our financial position, results of operations or cash flows. We are a defendant in certain claims and litigation arising out of operations in the ordinary course of business, 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. 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. During 2014, the 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 consolidated financial statements. We have also been informed by the IRS that our 2012 and 2013 tax returns will be examined, and we anticipate that examination beginning during 2017. The IRS examination team also completed its examination of two U.S. subsidiaries of Frontier Drilling for 2011, and proposed no changes to those returns. On August 1, 2014, Noble-UK completed 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 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 the Settlement Agreement with Paragon Offshore under which, in exchange for a full and unconditional release of any claims by Paragon Offshore in connection with the Spin-off (including fraudulent conveyance claims that could be brought on behalf of Paragon Offshore’s creditors), we agreed to provide certain tax bonding in Mexico as well as assume certain tax liabilities and the administration of Mexican tax claims for specified years. The bonding to be provided by Noble-UK was a key benefit to Paragon Offshore of the Settlement Agreement, which was subject to bankruptcy court confirmation as part of a bankruptcy plan. The Prior Plan was rejected by the bankruptcy court in October 2016. In April 2017, Paragon Offshore filed an updated disclosure statement and a New Plan in its bankruptcy proceeding. Under the New Plan, including Paragon Offshore’s revised business plan, Paragon Offshore will no longer need the Mexican tax bonding that Noble was to provide under the Settlement Agreement. As a result, the Settlement Agreement is no longer applicable to the anticipated ongoing business of Paragon Offshore. 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 litigation trust to pursue litigation against us. We continue to discuss our continuing relationship with Paragon Offshore, including the possibility of entering into a new settlement agreement. There can be no assurance that we will reach any settlement agreement with Paragon Offshore. If we do not enter into a settlement agreement with Paragon Offshore, we expect Paragon Offshore or its creditors would use the funds in the litigation trust to pursue claims against us relating to the Spin-off, including any alleged fraudulent conveyance claims. We continue to believe that Paragon Offshore, at the time of the Spin-off, was properly funded, solvent and had appropriate liquidity and that any fraudulent conveyance claim or other claim related to the Spin-off that may be brought by Paragon Offshore or its creditors would be without merit and would be contested vigorously by us. If litigation is instituted against Noble and we are unsuccessful in defending such claims, it could have a material adverse effect on our financial position, results of operations and/or cash flows. In the course of its bankruptcy, Paragon Offshore may elect to reject the Separation Agreements. If Paragon Offshore rejects the Separation Agreements, the indemnity obligations that Paragon Offshore may owe us under the Separation Agreements would terminate, 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. We could, however, pursue claims against Paragon Offshore for such indemnity amounts in the bankruptcy proceeding. Any such claims would be unsecured claims in the bankruptcy. Likewise, any indemnity obligations that we may owe 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, would also be extinguished. We do not expect that a rejection of the Separation Agreements by Paragon Offshore would have a material adverse effect on our financial condition or liquidity. However, any loss we experience with respect to which we are unable to secure indemnification from Paragon Offshore 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. Audit claims of approximately $49 million attributable to income and other business taxes have been assessed against Noble entities in Mexico. In addition, under the TSA, we must indemnify Paragon Offshore for final assessed amounts in respect of approximately $9 million of tax audit claims arising from Noble's Mexican business that was conducted through Paragon Offshore-retained entities prior to the Spin-off. If the Separation Agreements, including the TSA, are terminated, we would no longer have an obligation to indemnify Paragon Offshore for such amounts. In January 2015, Noble received an official notification of a ruling from the Second Chamber of the Supreme Court in Mexico. The ruling settled an ongoing dispute in Mexico relating to the classification of a Noble subsidiary’s business activity and the applicable rate of depreciation under the Mexican law applicable to the activities of that subsidiary. The ruling did not result in any additional tax liability to Noble. Additionally, the ruling is only applicable to the Noble subsidiary named in the ruling and, therefore, does not establish the depreciation rate applicable to the assets of other Noble subsidiaries. We will continue to contest future assessments received, and can make no assurances regarding the ultimate outcome of these tax claims or our obligations to pay additional taxes in respect of these tax claims. Paragon Offshore has received certain tax assessments attributable to income, customs and other business taxes in Brazil, including $46 million relating to Noble’s business that operated through a Paragon Offshore-retained entity in Brazil prior to the Spin-off. Under the TSA, we must indemnify Paragon Offshore for all final assessed amounts that are related to Noble’s Brazil business if and when such payments become due. If the Separation Agreements, including the TSA, are terminated, we would no longer have an obligation to indemnify Paragon Offshore for such amounts. We have contested, or intend to contest or cooperate with Paragon Offshore in Brazil where it is contesting, the assessments described above, including through litigation if necessary, and we believe the ultimate resolution, for which we have not made any accrual, will not have a material adverse effect on our consolidated financial statements. Tax authorities may issue additional assessments or pursue legal actions as a result of tax audits and we cannot predict or provide assurance as to the ultimate outcome of such assessments and legal actions or our ability to collect indemnities from Paragon Offshore under the TSA. We have been notified by Petrobras that it is currently challenging assessments by Brazilian tax authorities of withholding taxes associated with the provision of drilling rigs for its operations in Brazil during 2008 and 2009. Petrobras has also notified us that if Petrobras must ultimately pay such withholding taxes, it will seek reimbursement from us for the portion allocable to our drilling rigs. The amount of withholding tax that Petrobras indicates may be allocable to Noble drilling rigs is approximately $25 million. We believe that our contract with Petrobras requires Petrobras to indemnify us for these withholding taxes. We will, if necessary, vigorously defend our rights. We maintain certain insurance coverage against specified marine perils, which includes physical damage and loss of hire to our drilling rigs along with other associated coverage common in our industry. We maintain a physical damage deductible on our rigs of $25 million per occurrence. With respect to the U.S. Gulf of Mexico, hurricane risk has generally resulted in more restrictive and expensive coverage for U.S. named windstorm perils, and we have opted in certain years to maintain limited or no windstorm coverage. Our current program provides for $500 million in named windstorm coverage in the U.S. Gulf of Mexico. The loss of hire coverage applies only to our rigs operating under contract with a dayrate equal to or greater than $200,000 a day and is subject to a 45-day waiting period for each unit and each occurrence. Although we maintain insurance in the geographic areas in which we operate, pollution, reservoir damage and environmental risks generally are not fully insurable. Our insurance policies and contractual rights to indemnity may not adequately cover our losses or may have exclusions of coverage for some losses. We do not have insurance coverage or rights to indemnity for all risks, including loss of hire insurance on most of the rigs in our fleet. Uninsured exposures may include expatriate activities prohibited by U.S. laws and regulations, radiation hazards, certain loss or damage to property on board our rigs and losses relating to shore-based terrorist acts, strikes or cyber risks. If a significant accident or other event occurs and is not fully covered by insurance or contractual indemnity, it could materially adversely affect our financial position, results of operations or cash flows. Additionally, there can be no assurance that those parties with contractual obligations to indemnify us will necessarily be financially able to indemnify us against all these risks. We carry protection and indemnity insurance covering marine third party liability exposures, which also includes coverage for employer’s liability resulting from personal injury to our offshore drilling crews. Our protection and indemnity policy currently has a standard deductible of $10 million per occurrence, with maximum liability coverage of $750 million. 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.

Commitments and Contingencies

In January 2017, a subsidiary of Transocean Ltd. 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 when we constructed the rigs, and we do not believe that our rigs infringe the Transocean patents, which are now expired. We intend to defend ourselves vigorously against this claim.

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 pled guilty to oil record book, ballast record and required hazardous condition reporting violations with respect to the Noble Discoverer and an oil record book violation with respect to the Kulluk. The subsidiary paid $8.2 million in fines and $4 million in community service payments and was placed on probation for four years, provided that we may petition the court for early dismissal of probation after three years. If, during the term of probation, the subsidiary fails to adhere to the terms of the plea agreement, the DOJ may withdraw from the plea agreement and would be free to prosecute the subsidiary on all charges arising out of its investigation, including any charges dismissed pursuant to the terms of the plea agreement, as well as potentially other charges. We also implemented a comprehensive environmental compliance plan in connection with the settlement.

We have used a commercial agent in Brazil in connection with our Petróleo Brasileiro S.A. (“Petrobras”) drilling contracts. We understand that this agent has 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 is now substantially complete, of our relationship with the agent and with Petrobras. We are in contact with the SEC, the Brazilian federal prosecutor’s office and the DOJ about this matter. We are cooperating 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.

We are from time to time a party to various lawsuits that are incidental to our operations in which the claimants seek an unspecified amount of monetary damages for personal injury, including injuries purportedly resulting from exposure to asbestos on drilling rigs and associated facilities. At March 31, 2017, there were 43 asbestos related lawsuits in which we are one of many defendants. These lawsuits have been filed in the United States in the states of Louisiana and Mississippi. We intend to vigorously defend against the litigation. We do not believe the ultimate resolution of these matters will have a material adverse effect on our financial position, results of operations or cash flows.

We are a defendant in certain claims and litigation arising out of operations in the ordinary course of business, 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.

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.

During 2014, the 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 consolidated financial statements. We have also been informed by the IRS that our 2012 and 2013 tax returns will be examined, and we anticipate that examination beginning during 2017. The IRS examination team also completed its examination of two U.S. subsidiaries of Frontier Drilling for 2011, and proposed no changes to those returns.

On August 1, 2014, Noble-UK completed 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 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 the Settlement Agreement with Paragon Offshore under which, in exchange for a full and unconditional release of any claims by Paragon Offshore in connection with the Spin-off (including fraudulent conveyance claims that could be brought on behalf of Paragon Offshore’s creditors), we agreed to provide certain tax bonding in Mexico as well as assume certain tax liabilities and the administration of Mexican tax claims for specified years. The bonding to be provided by Noble-UK was a key benefit to Paragon Offshore of the Settlement Agreement, which was subject to bankruptcy court confirmation as part of a bankruptcy plan. The Prior Plan was rejected by the bankruptcy court in October 2016.

In April 2017, Paragon Offshore filed an updated disclosure statement and a New Plan in its bankruptcy proceeding. Under the New Plan, including Paragon Offshore’s revised business plan, Paragon Offshore will no longer need the Mexican tax bonding that Noble was to provide under the Settlement Agreement. As a result, the Settlement Agreement is no longer applicable to the anticipated ongoing business of Paragon Offshore. 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 litigation trust to pursue litigation against us.

We continue to discuss our continuing relationship with Paragon Offshore, including the possibility of entering into a new settlement agreement. There can be no assurance that we will reach any settlement agreement with Paragon Offshore. If we do not enter into a settlement agreement with Paragon Offshore, we expect Paragon Offshore or its creditors would use the funds in the litigation trust to pursue claims against us relating to the Spin-off, including any alleged fraudulent conveyance claims. We continue to believe that Paragon Offshore, at the time of the Spin-off, was properly funded, solvent and had appropriate liquidity and that any fraudulent conveyance claim or other claim related to the Spin-off that may be brought by Paragon Offshore or its creditors would be without merit and would be contested vigorously by us. If litigation is instituted against Noble and we are unsuccessful in defending such claims, it could have a material adverse effect on our financial position, results of operations and/or cash flows.

In the course of its bankruptcy, Paragon Offshore may elect to reject the Separation Agreements. If Paragon Offshore rejects the Separation Agreements, the indemnity obligations that Paragon Offshore may owe us under the Separation Agreements would terminate, 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. We could, however, pursue claims against Paragon Offshore for such indemnity amounts in the bankruptcy proceeding. Any such claims would be unsecured claims in the bankruptcy. Likewise, any indemnity obligations that we may owe 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, would also be extinguished. We do not expect that a rejection of the Separation Agreements by Paragon Offshore would have a material adverse effect on our financial condition or liquidity. However, any loss we experience with respect to which we are unable to secure indemnification from Paragon Offshore 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.

Audit claims of approximately $49 million attributable to income and other business taxes have been assessed against Noble entities in Mexico. In addition, under the TSA, we must indemnify Paragon Offshore for final assessed amounts in respect of approximately $9 million of tax audit claims arising from Noble's Mexican business that was conducted through Paragon Offshore-retained entities prior to the Spin-off. If the Separation Agreements, including the TSA, are terminated, we would no longer have an obligation to indemnify Paragon Offshore for such amounts.

In January 2015, Noble received an official notification of a ruling from the Second Chamber of the Supreme Court in Mexico. The ruling settled an ongoing dispute in Mexico relating to the classification of a Noble subsidiary’s business activity and the applicable rate of depreciation under the Mexican law applicable to the activities of that subsidiary. The ruling did not result in any additional tax liability to Noble. Additionally, the ruling is only applicable to the Noble subsidiary named in the ruling and, therefore, does not establish the depreciation rate applicable to the assets of other Noble subsidiaries. We will continue to contest future assessments received, and can make no assurances regarding the ultimate outcome of these tax claims or our obligations to pay additional taxes in respect of these tax claims.

Paragon Offshore has received certain tax assessments attributable to income, customs and other business taxes in Brazil, including $46 million relating to Noble’s business that operated through a Paragon Offshore-retained entity in Brazil prior to the Spin-off. Under the TSA, we must indemnify Paragon Offshore for all final assessed amounts that are related to Noble’s Brazil business if and when such payments become due. If the Separation Agreements, including the TSA, are terminated, we would no longer have an obligation to indemnify Paragon Offshore for such amounts.

We have contested, or intend to contest or cooperate with Paragon Offshore in Brazil where it is contesting, the assessments described above, including through litigation if necessary, and we believe the ultimate resolution, for which we have not made any accrual, will not have a material adverse effect on our consolidated financial statements. Tax authorities may issue additional assessments or pursue legal actions as a result of tax audits and we cannot predict or provide assurance as to the ultimate outcome of such assessments and legal actions or our ability to collect indemnities from Paragon Offshore under the TSA.

We have been notified by Petrobras that it is currently challenging assessments by Brazilian tax authorities of withholding taxes associated with the provision of drilling rigs for its operations in Brazil during 2008 and 2009. Petrobras has also notified us that if Petrobras must ultimately pay such withholding taxes, it will seek reimbursement from us for the portion allocable to our drilling rigs. The amount of withholding tax that Petrobras indicates may be allocable to Noble drilling rigs is approximately $25 million. We believe that our contract with Petrobras requires Petrobras to indemnify us for these withholding taxes. We will, if necessary, vigorously defend our rights.

We maintain certain insurance coverage against specified marine perils, which includes physical damage and loss of hire to our drilling rigs along with other associated coverage common in our industry. We maintain a physical damage deductible on our rigs of $25 million per occurrence. With respect to the U.S. Gulf of Mexico, hurricane risk has generally resulted in more restrictive and expensive coverage for U.S. named windstorm perils, and we have opted in certain years to maintain limited or no windstorm coverage. Our current program provides for $500 million in named windstorm coverage in the U.S. Gulf of Mexico. The loss of hire coverage applies only to our rigs operating under contract with a dayrate equal to or greater than $200,000 a day and is subject to a 45-day waiting period for each unit and each occurrence.

Although we maintain insurance in the geographic areas in which we operate, pollution, reservoir damage and environmental risks generally are not fully insurable. Our insurance policies and contractual rights to indemnity may not adequately cover our losses or may have exclusions of coverage for some losses. We do not have insurance coverage or rights to indemnity for all risks, including loss of hire insurance on most of the rigs in our fleet. Uninsured exposures may include expatriate activities prohibited by U.S. laws and regulations, radiation hazards, certain loss or damage to property on board our rigs and losses relating to shore-based terrorist acts, strikes or cyber risks. If a significant accident or other event occurs and is not fully covered by insurance or contractual indemnity, it could materially adversely affect our financial position, results of operations or cash flows. Additionally, there can be no assurance that those parties with contractual obligations to indemnify us will necessarily be financially able to indemnify us against all these risks.

We carry protection and indemnity insurance covering marine third party liability exposures, which also includes coverage for employer’s liability resulting from personal injury to our offshore drilling crews. Our protection and indemnity policy currently has a standard deductible of $10 million per occurrence, with maximum liability coverage of $750 million.

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.