Organization and Basis of Presentation (Policies)	6 Months Ended
Organization and Basis of Presentation (Policies)	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidation	The accompanying unaudited condensed consolidated financial statements of Noble-UK and Noble-Cayman have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) as they pertain to Quarterly Reports on Form 10-Q. Accordingly, certain information and disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to such rules and regulations. The unaudited financial statements reflect all adjustments which are, in the opinion of management, necessary for a fair statement of the financial position and results of operations for the interim periods, on a basis consistent with the annual audited consolidated financial statements. All such adjustments are of a recurring nature. The December 31, 2017 Condensed Consolidated Balance Sheets presented herein are derived from the December 31, 2017 audited consolidated financial statements. These interim financial statements should be read in conjunction with the consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended December 31, 2017, filed by both Noble-UK and Noble-Cayman. The results of operations for interim periods are not necessarily indicative of the results to be expected for the full year.
New Accounting Pronouncements	Accounting Standards Adopted In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-9, which creates Accounting Standards Codification (“ASC”) Topic 606, “Revenue from Contracts with Customers,” and supersedes the revenue recognition requirements in Topic 605, “Revenue Recognition,” including most industry-specific revenue recognition guidance throughout the Industry Topics of the Codification. In addition, ASU No. 2014-9 supersedes the cost guidance in Subtopic 605-35, “Revenue Recognition—Construction-Type and Production-Type Contracts,” and creates new Subtopic 340-40, “Other Assets and Deferred Costs—Contracts with Customers.” Under the new guidance, revenue is recognized when a customer obtains control of promised goods or services and in an amount that reflects the consideration the entity expects to receive in exchange for those goods or services. We adopted ASU 2014-09 and its related amendments, or collectively Topic 606, effective January 1, 2018 using the modified retrospective implementation method. Accordingly, we have applied the five-step method outlined in Topic 606 for determining when and how revenue is recognized to all contracts that were not completed as of the date of adoption. Revenues for reporting periods beginning after January 1, 2018 are presented under Topic 606, while prior period amounts have not been adjusted and continue to be reported under the previous revenue recognition guidance. For contracts that were modified before the effective date, we have considered the modification guidance within the new standard and determined that the revenue recognized and contract balances recorded prior to adoption for such contracts were not impacted. While Topic 606 requires additional disclosure of the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers, its adoption has not had a material impact on the measurement or recognition of our revenues. Our modified retrospective adoption, for which we were not required to make any material changes to the prior year presentation, did not have a material effect on our condensed consolidated financial statements. In October 2016, the FASB issued ASU No. 2016-16, which amends ASC Topic 740, “Income Taxes.” The amendments in this update improve the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. This standard is effective for interim and annual reporting periods beginning after December 15, 2017. We have adopted the new standard effective January 1, 2018 under the modified retrospective approach. Accordingly, “Other Assets” is reduced in our Condensed Consolidated Balance Sheet with a cumulative adjustment to retained earnings of approximately $149.9 million. In February 2018, the FASB issued ASU No. 2018-2, which amends ASC Topic 220, “Income Statement—Reporting Comprehensive Income.” The amendments in this update allow for a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act (the “Act”). This standard is effective for interim and annual reporting periods beginning after December 15, 2018 with early application permitted. We have elected to adopt the new standard effective January 1, 2018 under the modified retrospective approach. The amendment should be applied on a retrospective basis to each period in which the effect of the change in the U.S. federal corporate income tax rate in the Act was recognized. As a result of the retrospective application, we will reduce “Accumulated Other Comprehensive Income” in our Condensed Consolidated Balance Sheet with a cumulative adjustment to “Retained Earnings” of approximately $5.5 million. In March 2017, the FASB issued ASU No. 2017-7, which amends ASC Topic 715, “Compensation —Retirement Benefits; Improving the Presentation of Net Periodic Pension Cost and Postretirement Benefits Cost.” The amendments in this update require that an employer disaggregate the service cost component from the other components of net benefit cost for an entity's defined benefit pension and other postretirement plans. The amendments also provide explicit guidance on how to present the service cost component and the other components of net benefit cost in the income statement and allow only the service cost component of net benefit cost to be eligible for capitalization. The amendments in this update require that an employer report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit costs, as defined in paragraphs 715-30-35-4 and 715-60-35-9, are required to be presented in the income statement separately from the service cost component and outside of income from operations. We adopted ASU No. 2017-7 effective January 1, 2018 and accordingly, we have made certain reclassifications between our “Contract drilling services” costs and “Interest income and other, net” on our Condensed Consolidated Statement of Operations. Issued Accounting Standards In February 2016, the FASB issued ASU No. 2016-2, which creates ASC Topic 842, “Leases.” This standard is effective for interim and annual reporting periods beginning after December 15, 2018. We expect to adopt, on a modified retrospective basis, ASC 842 effective January 1, 2019. Our adoption requires that, as lessees, we recognize a right to use asset and lease liability. In addition, as lessors, our drilling contracts contain a lease component, which requires revenue presentation analysis. The ultimate effect on our consolidated financial statements, will be based on an evaluation of the contract-specific facts and circumstances. We do not expect our adoption to materially affect our Condensed Consolidated Balance Sheet, Condensed Consolidated Statement of Operations, or Condensed Consolidated Statement of Cash Flows. We are currently evaluating what other effect, if any, ASC 842 will have on our condensed consolidated financial statements and related disclosures. With the exception of the updated standards discussed above, there have been no new accounting pronouncements not yet effective that have significance, or potential significance, to our condensed consolidated financial statements.
Revenue	Dayrate Drilling Revenue. Our drilling contracts generally provide for payment on a dayrate basis, with higher rates for periods when the drilling unit is operating and lower rates or zero rates for periods when drilling operations are interrupted or restricted. The dayrate invoices billed to the customer are typically determined based on the varying rates applicable to the specific activities performed on an hourly basis. Such dayrate consideration is allocated to the distinct hourly increment it relates to within the contract term, and therefore, recognized in line with the contractual rate billed for the services provided for any given hour. Mobilization/Demobilization Revenue. We may receive fees (on either a fixed lump-sum or variable dayrate basis) for the mobilization and demobilization of our rigs. These activities are not considered to be distinct within the context of the contract and, therefore, the associated revenue is allocated to the overall performance obligation and the associated pre-operating costs are deferred. We record a contract liability for mobilization fees received and a deferred asset for costs. Both revenue and pre-operating costs are recognized ratably over the initial term of the related drilling contract. In most contracts, there is uncertainty as to the amount of expected demobilization revenue due to contractual provisions that stipulate that certain conditions must be present at contract completion for such revenue to be received and as to the amount thereof, if any. For example, contractual provisions may require that a rig demobilize a certain distance before the demobilization revenue is payable or the amount may vary dependent upon whether or not the rig has additional contracted work within a certain distance from the wellsite. Therefore, the estimate for such revenue may be constrained, as described earlier, depending on the facts and circumstances pertaining to the specific contract. We assess the likelihood of receiving such revenue based on past experience and knowledge of the market conditions. In cases where demobilization revenue is expected to be received upon contract completion, it is estimated as part of the overall transaction price at contract inception and recognized in earnings ratably over the initial term of the contract with an offset to an accretive contract asset. Contract Preparation Revenue. Some of our drilling contracts require downtime before the start of the contract to prepare the rig to meet customer requirements. At times, we may be compensated by the customer for such work (on either a fixed lump-sum or variable dayrate basis). These activities are not considered to be distinct within the context of the contract and, therefore, the related revenue is allocated to the overall performance obligation and recognized ratably over the initial term of the related drilling contract. We record a contract liability for contract preparation fees received, which is amortized ratably to contract drilling revenue over the initial term of the related drilling contract. Bonuses, Penalties and Other Variable Consideration. We may receive bonus increases to revenue or penalty decreases to revenue. Based on historical data, and ongoing communication with the operator/customer, we are able to reasonably estimate this variable consideration. We will record such estimated variable consideration and re-measure our estimates at each reporting date. For revenue estimated, but not received, we will record to “Prepaid expenses and other current assets” on our Condensed Consolidated Balance Sheets. Capital Modification Revenue. From time to time, we may receive fees from our customers for capital improvements to our rigs to meet contractual requirements (on either a fixed lump-sum or variable dayrate basis). Such revenue is allocated to the overall performance obligation and recognized ratably over the initial term of the related drilling contract as these activities are integral to our drilling activities and are not considered to be a stand-alone service provided to the customer within the context of our contracts. We record a contract liability for such fees and recognize them ratably as contract drilling revenue over the initial term of the related drilling contract. Revenues Related to Reimbursable Expenses. We generally receive reimbursements from our customers for the purchase of supplies, equipment, personnel services and other services provided at their request in accordance with a drilling contract or other agreement. Such reimbursable revenue is variable and subject to uncertainty, as the amounts received and timing thereof is highly dependent on factors outside of our influence. Accordingly, reimbursable revenue is constrained revenue and not included in the total transaction price until the uncertainty is resolved, which typically occurs when the related costs are incurred on behalf of a customer. We are generally considered a principal in such transactions and record the associated revenue at the gross amount billed to the customer as “Revenues related to reimbursable expenses” in our Condensed Consolidated Statements of Operations. Such amounts are recognized ratably over the period within the contract term, during which the corresponding goods and services are to be consumed.
Contract Balances	Contract Balances Accounts receivable are recognized when the right to consideration becomes unconditional based upon contractual billing schedules. Payment terms on invoiced amounts are typically 30 days. Current contract asset and liability balances are included in “prepaid expenses and other current assets” and “other current liabilities,” respectively, and noncurrent contract assets and liabilities are included in “other assets” and “other liabilities,” respectively, on our Condensed Consolidated Balance Sheets.

Disclosure of accounting policy for trade and other accounts receivable, and finance, loan and lease receivables, including those classified as held for investment and held for sale. This disclosure may include (1) the basis at which such receivables are carried in the entity's statements of financial position (2) how the level of the valuation allowance for receivables is determined (3) when impairments, charge-offs or recoveries are recognized for such receivables (4) the treatment of origination fees and costs, including the amortization method for net deferred fees or costs (5) the treatment of any premiums or discounts or unearned income (6) the entity's income recognition policies for such receivables, including those that are impaired, past due or placed on nonaccrual status and (7) the treatment of foreclosures or repossessions (8) the nature and amount of any guarantees to repurchase receivables.