Rowan Companies 10-Q 31 Oct 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 24, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	ROWAN COMPANIES PLC
Entity Central Index Key	85,408
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		127,068,684
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Document Period End Date	Sep. 30, 2018

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
REVENUE	$ 192.9	$ 291.6	$ 645.4	$ 986.1
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	182.3	168.7	516	508.8
Depreciation and amortization	99	103.4	294.3	304
Selling, general and administrative	26.6	24.9	77.4	71.3
Loss on disposals of property and equipment	1.5	2.8	5	9.3
Total costs and expenses	309.4	299.8	892.7	893.4
Equity in earnings of unconsolidated subsidiary	3.1	0	3.4	0
INCOME (LOSS) FROM OPERATIONS	(113.4)	(8.2)	(243.9)	92.7
OTHER INCOME (EXPENSE):
Interest expense	(39.2)	(38.5)	(116.6)	(117)
Interest income	8	3.7	22.6	8.9
Gain (loss) on extinguishment of debt	0	(0.5)	0	1.7
Other - net	4	0.8	10.6	3.7
Total other (expense) - net	(27.2)	(34.5)	(83.4)	(102.7)
LOSS BEFORE INCOME TAXES	(140.6)	(42.7)	(327.3)	(10)
Provision (benefit) for income taxes	3.5	(21.8)	5.8	29.3
NET LOSS	$ (144.1)	$ (20.9)	$ (333.1)	$ (39.3)
NET LOSS PER SHARE - BASIC AND DILUTED (in dollars per share)	$ (1.13)	$ (0.17)	$ (2.63)	$ (0.31)
Weighted Average Number of Shares Outstanding, Basic and Diluted	127.1	126.2	126.9	126.1

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
NET LOSS	$ (144.1)	$ (20.9)	$ (333.1)	$ (39.3)
OTHER COMPREHENSIVE INCOME (LOSS):
Net changes in pension and other postretirement plan assets and benefit obligations recognized in other comprehensive income, net of income tax expense of $0 for both the three months ended September 30, 2018 and 2017, and $4.2 and $0 for the nine months ended September 30, 2018 and 2017, respectively (see Note 5).	0	0	15.9	0
Net reclassification adjustment for amounts recognized in net loss as a component of net periodic benefit cost, net of income tax (benefit) expense of ($0.1) and $0.5 for the three months ended September 30, 2018 and 2017, respectively, and $1.1 and $1.5 for the nine months ended September 30, 2018, and 2017, respectively (see Note 5 and 9).	(0.7)	1	4	2.7
Total Other Comprehensive Income	(0.7)	1	19.9	2.7
COMPREHENSIVE LOSS	$ (144.8)	$ (19.9)	$ (313.2)	$ (36.6)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net reclassification adjustments for amounts recognized in net income as a component of net periodic benefit cost, tax expense	$ (0.1)	$ 0.5	$ 1.1	$ 1.5
Net changes in pension and other postretirement plan assets and benefit obligations recognized in other comprehensive income, tax expense	$ 0	$ 0	$ 4.2	$ 0

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 1,032.4	$ 1,332.1
Receivables - trade and other	281.5	212.8
Prepaid expenses and other current assets	31.4	15.5
Total current assets	1,345.3	1,560.4
PROPERTY AND EQUIPMENT:
Drilling equipment	8,864.1	8,697.8
Other property and equipment	140.9	136.1
Property and equipment - gross	9,005	8,833.9
Less accumulated depreciation and amortization	2,566.9	2,281.2
Property and equipment - net	6,438.1	6,552.7
Long-term note receivable from unconsolidated subsidiary	269	270.2
Investment in unconsolidated subsidiary	34.3	30.9
Other assets	44.7	44.1
TOTAL ASSETS	8,131.4	8,458.3
CURRENT LIABILITIES:
Current portion of long-term debt	201.1	0
Accounts payable - trade	112.2	97.2
Deferred revenues	17.8	1.1
Accrued liabilities	122.2	159.1
Total current liabilities	453.3	257.4
Long-term debt	2,309.6	2,510.3
Other liabilities	268.6	293.6
Deferred income taxes - net	11.1	10.9
Commitments and contingent liabilities
SHAREHOLDERS' EQUITY:
Class A Ordinary Shares, $0.125 par value; 128.2 and 128.1 shares issued, respectively; 127.1 and 126.3 shares outstanding, respectively	16	16
Additional paid-in capital	1,497.4	1,488.6
Retained earnings	3,824.8	4,109.7
Cost of 1.1 and 1.8 treasury shares, respectively	(7.7)	(9.3)
Accumulated other comprehensive loss	(241.7)	(218.9)
Total shareholders' equity	5,088.8	5,386.1
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 8,131.4	$ 8,458.3

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares shares in Millions	Sep. 30, 2018	Dec. 31, 2017
SHAREHOLDERS' EQUITY:
Treasury shares (in shares)	1.1	1.8
Common Class A [Member]
SHAREHOLDERS' EQUITY:
Common stock, par value (in dollars per share)	$ 0.125	$ 0.125
Common stock, shares issued (in shares)	128.2	128.1
Common stock, shares outstanding (in shares)	127.1	126.3

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Class A ordinary shares/ Common stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Treasury shares [Member]	Accumulated other comprehensive income (loss) [Member]
Beginning Balance (in shares) at Dec. 31, 2016		125.5
Beginning Balance at Dec. 31, 2016	$ 5,113.9	$ 16	$ 1,471.7	$ 3,830.4	$ (7.2)	$ (197)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net shares issued (acquired) under share-based compensation plans (in shares)		0.7
Net shares issued (acquired) under share-based compensation plans	(4.4)	$ 0	(2.3)		(2.1)
Share-based compensation	15.2		15.2
Retirement benefit adjustments, net of taxes	2.7					2.7
Net loss	(39.3)			(39.3)
Ending Balance (in shares) at Sep. 30, 2017		126.2
Ending Balance at Sep. 30, 2017	5,294.7	$ 16	1,484.6	3,997.7	(9.3)	(194.3)
Beginning Balance (in shares) at Jun. 30, 2017		126.2
Beginning Balance at Jun. 30, 2017	5,310.1	$ 16	1,480.1	4,018.6	(9.3)	(195.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net shares issued (acquired) under share-based compensation plans	(0.1)		(0.1)
Share-based compensation	4.6		4.6
Retirement benefit adjustments, net of taxes	1					1
Net loss	(20.9)			(20.9)
Ending Balance (in shares) at Sep. 30, 2017		126.2
Ending Balance at Sep. 30, 2017	5,294.7	$ 16	1,484.6	3,997.7	(9.3)	(194.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standards (see Note 1)	206.6			206.6
Beginning Balance (in shares) at Dec. 31, 2017		126.3
Beginning Balance at Dec. 31, 2017	5,386.1	$ 16	1,488.6	4,109.7	(9.3)	(218.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net shares issued (acquired) under share-based compensation plans (in shares)		0.8
Net shares issued (acquired) under share-based compensation plans	(2.6)	$ 0	(4.2)		1.6
Share-based compensation	13		13
Retirement benefit adjustments, net of taxes	19.9					19.9
Other				(2.9)		2.9
Net loss	(333.1)			(333.1)
Ending Balance (in shares) at Sep. 30, 2018		127.1
Ending Balance at Sep. 30, 2018	5,088.8	$ 16	1,497.4	3,824.8	(7.7)	(241.7)
Beginning Balance (in shares) at Jun. 30, 2018		127
Beginning Balance at Jun. 30, 2018	5,229.7	$ 16	1,493.6	3,968.9	(7.8)	(241)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net shares issued (acquired) under share-based compensation plans	(0.6)		(0.7)		0.1
Share-based compensation	4.5		4.5
Retirement benefit adjustments, net of taxes	(0.7)					(0.7)
Net loss	(144.1)			(144.1)
Ending Balance (in shares) at Sep. 30, 2018		127.1
Ending Balance at Sep. 30, 2018	5,088.8	$ 16	$ 1,497.4	3,824.8	$ (7.7)	(241.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standards (see Note 1)	$ 5.5			$ 51.1		$ (45.6)

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Stockholders' Equity [Abstract]
Retirement benefit adjustments, taxes	$ 0.5	$ (0.1)	$ 5.3	$ 1.5

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (333.1)	$ (39.3)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	294.3	304
Equity in earnings of unconsolidated subsidiary	(3.4)	0
Deferred income taxes	(4.2)	32.8
Pension and other postretirement benefits expense (income)	(6.8)	5.1
Share-based compensation expense	19.4	19.5
Loss on disposals of property and equipment	5	9.3
Other	10.7	1.8
Changes in current assets and liabilities:
Receivables - trade and other	(34.5)	50.8
Prepaid expenses and other current assets	(15.2)	5.3
Accounts payable	9.9	(14.9)
Accrued income taxes	(9.4)	(1.3)
Other current liabilities	(19)	6.8
Other postretirement benefit claims paid	(1.2)	(2)
Contributions to pension plans	(20.1)	(23.9)
Deferred revenue	7.8	(70)
Net changes in other noncurrent assets and liabilities	(12.6)	(43)
Net cash provided by (used in) operating activities	(112.4)	241
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(116.9)	(78.6)
Purchase of rigs	(70.8)	0
Investment in unconsolidated subsidiary	0	(25)
Repayments of note receivable from unconsolidated subsidiary	2.3	0
Proceeds from disposals of property and equipment	8.1	1.5
Net cash used in investing activities	(177.3)	(102.1)
CASH FLOWS FROM FINANCING ACTIVITIES:
Reductions of long-term debt	0	(170)
Debt issue costs	6.1	0
Shares repurchased for tax withholdings on vesting of restricted share units	(3.9)	(4.4)
Net cash used in financing activities	(10)	(174.4)
DECREASE IN CASH AND CASH EQUIVALENTS	(299.7)	(35.5)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	1,332.1	1,255.5
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 1,032.4	$ 1,220

Nature of Operations and Basis

Nature of Operations and Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Basis of Presentation	Nature of Operations, Basis of Presentation and Summary of Significant Accounting Policies Rowan Companies plc, a public limited company incorporated under the laws of England and Wales, is a global provider of offshore contract drilling services to the oil and gas industry, with a focus on high-specification and harsh-environment jack-up rigs and ultra-deepwater drillships. As of September 30, 2018 , the Company operated in three segments: Deepwater, Jack-ups and ARO, the Company's 50 / 50 joint venture with Saudi Aramco. The Deepwater segment included four ultra-deepwater drillships. The Jack-ups segment was composed of 23 self-elevating jack-up rigs and included the impact of the various arrangements with ARO (see Note 3 ). As of September 30, 2018 , ARO owned a fleet of five self-elevating jack-up rigs for operation in the Arabian Gulf for Saudi Aramco. Effective October 1, 2018, the Company sold two jack-ups to ARO (see below). The Company contracts its drilling rigs, related equipment and work crews primarily on a day-rate basis in markets throughout the world, including the US GOM, U.K. and Norwegian sectors of the North Sea, the Middle East, the Mediterranean Sea and Trinidad. The financial statements included in this Quarterly Report are presented in USD and include the accounts of Rowan plc and its direct and indirect subsidiaries. Unless the context otherwise requires, the terms “Rowan,” and “Company” are used to refer to Rowan plc and its consolidated subsidiaries. Intercompany balances and transactions have been eliminated in consolidation. The financial statements included in this Quarterly Report have been prepared in accordance with US GAAP and the applicable rules and regulations of the SEC. Certain information and notes have been condensed or omitted as permitted by those rules and regulations. The financial information included in this report is unaudited, but management believes the accompanying financial statements contain all adjustments, which are of a normal recurring nature unless otherwise noted, necessary for a fair statement of the financial position, results of operations and cash flows for the interim periods presented. The preparation of the condensed consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. The Company’s results of operations and cash flows for the interim periods are not necessarily indicative of results to be expected for the full year. These financial statements should be read in conjunction with the audited consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (as recast in part on Forms 8-K filed with the SEC on May 9, 2018 and August 24, 2018). Proposed Merger of Rowan Companies plc and Ensco plc On October 7, 2018, the Company entered into a Transaction Agreement with Ensco, to effect a “merger-of-equals” transaction. In the Transaction Agreement each of the issued and outstanding Class A ordinary shares of the Company will be exchanged for 2.215 Class A ordinary shares of Ensco, each with a nominal value of $0.10 per share. The Transaction is being implemented by means of a court-sanctioned scheme of arrangement under Part 26 of the U.K. Companies Act 2006 (provided that the parties reserve the right under the Transaction Agreement to effect the acquisition by way of a contractual takeover offer as defined in section 974 of the U.K. Companies Act 2006 in certain circumstances). The resulting new combined company will be renamed and trade under a new ticker symbol on the New York Stock Exchange. The completion of the Transaction is subject to various closing conditions, including, among other things, (i) the receipt of certain approvals of the Company shareholders and the Ensco shareholders, (ii) the sanction of a court-sanctioned scheme of arrangement by the High Court of Justice of England and Wales, (iii) the receipt of certain required regulatory approvals or elapse of certain review periods with respect thereto, including those in the U.S., U.K. and Kingdom of Saudi Arabia, (iv) the absence of legal restraints prohibiting or restraining the Transaction and (v) the absence of any law or order reasonably expected to result in the dissolution of ARO, or the sale, disposition, forfeiture or nationalization of the Company's interest in ARO. Additionally, the Transaction agreement contains certain termination rights and associated fees and no solicitation provisions. Sale of Rigs to ARO On October 10, 2018, the Company concluded the sale of two jack-up rigs, the Scooter Yeargain and the Hank Boswell , to ARO. Transactions included (1) equal cash contributions to ARO by each of Rowan and Saudi Aramco, (2) the receipt of cash from both Rowan and Saudi Aramco in exchange for shareholder notes, (3) the subsequent sale of two rigs and related assets to ARO by Rowan in exchange for cash, and (4) the distribution by ARO of excess cash in the amount of approximately $90 million to each party, to be applied as a repayment to each party's shareholder note, maintaining each party’s 50% ownership interest in ARO following such asset sales. In addition to the 50% equity stake in ARO, the Company has a total of $445 million of shareholder notes due from ARO as of October 1, 2018. By agreement of the parties, this transaction was effective October 1, 2018, at which point the Scooter Yeargain and Hank Boswell each are deemed to have commenced a new three-year contract with Saudi Aramco. Anadarko Early Termination Revenue During the second quarter of 2018, the Company recognized $27.8 million of revenue related to an early termination fee from Anadarko Petroleum Corporation (“Anadarko”) pursuant to the Company’s drilling contract for the drillship Rowan Resolute (the “Anadarko Contract”). Termination of the Anadarko Contract became effective on June 1, 2018, and the early termination fee was a lump sum payment for the remainder of the term of the Anadarko Contract, originally scheduled to terminate on August 6, 2018, at a rate of $418,400 per day. Revenue Recognition In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (ASC 606) , which sets forth a global standard for revenue recognition and replaces most existing industry-specific guidance. ASC 606 requires an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company adopted ASC 606, effective January 1, 2018, utilizing the modified retrospective approach and applied ASC 606 to all outstanding revenue contracts. In adopting ASC 606, the Company's revenue recognition differs from its historical revenue recognition pattern primarily as it relates to demobilization revenue. Such revenue, which was recognized upon completion of a contract under legacy accounting, is now estimated at contract inception and recognized over the term of the contract under the new guidance for customer contracts that have unconstrained demobilization provisions. Upon adoption of this standard as of January 1, 2018, the Company recognized a $5.5 million increase to retained earnings related to unconstrained demobilization provisions. Subsequently, during the first quarter of 2018, the Company received a $5.5 million cash payment for such demobilization related to one of the Company's contracts. The adoption of this standard did not have a material impact on our statements of operations or statements of cash flows. Typical contractual arrangements The Company contracts its drilling rigs, related equipment and work crews primarily on a “day rate” basis. Under day rate contracts, the Company generally receives a fixed amount per day for each day it is performing drilling or related services. In addition, customers may pay all or a portion of the cost of moving equipment and personnel to and from the well site. Contracts generally range in duration from one month to multiple years or alternatively may be based on a set number of wells. Both duration types can include additional option periods at the discretion of the customer which can be at a set price or may be determined upon exercise of the option. The contractual day rate generally varies based on the status of the drilling operations and generally includes an operating rate, move rate, repair rate, force majeure, standby rate, or other fixed type of day rate specified in the contract. Other fees may be stipulated in the contract related to mobilization and demobilization of the rig, upfront preparation and/or upgrades, penalties, performance bonuses and reimbursements for third party charges or requested modifications. Termination clauses are also specified and generally allow the customer to cancel for lack of performance by the contractor with no related fee or for convenience for an early termination fee, typically calculated as a standby rate multiplied by the days remaining in the firm term in the contract often reduced by a specified percentage. Performance obligations and transaction price Customers generally contract for a comprehensive agreement to provide integrated services to operate a rig and drill a well. Drillers are seen by the operator as the overseer of all services and are compensating the driller to provide that entire suite of services. In identifying performance obligations, ASC 606 series guidance states that a contract may contain a single performance obligation composed of a series of distinct goods or services if 1) each distinct good or service is substantially the same and would meet the criteria to be a performance obligation satisfied over time and 2) each distinct good or service is measured using the same method as it relates to the satisfaction of the overall performance obligation. The Company determined that the delivery of day rate drilling services is within the scope of the series guidance as both criteria noted above are met. Specifically, 1) each distinct increment of service (i.e. hour available to drill) that the driller promises to transfer represents a performance obligation that would meet the criteria for recognizing revenue over time, and 2) the driller would use the same method for measuring progress toward satisfaction of the performance obligation for each distinct increment of service in the series. Consideration for activities that are not distinct within the scope of our contracts, such as mobilization, demobilization and upgrade/modification, and do not align with a distinct time increment within the contract term are allocated across the single performance obligation and are recognized over the expected recognition period in proportion to the passage of each hour available to drill. Consideration for activities which align with a distinct time increment within the contract term is recognized in the period when the services are performed. The transaction price for a drilling contract is based on the amount of consideration the Company expects to be entitled for providing drilling services over the specified term and includes both fixed amounts and unconstrained variable amounts. Typically, at contract commencement, the only fixed/known consideration components of a drilling contract are negotiated lump-sum amounts to be received for reimbursement of costs incurred for mobilization, demobilization (where it is contractually guaranteed) and/or rig modifications or upgrades. The Company estimates variable consideration using the expected value method and includes the amount in transaction price to the extent it is not constrained. Variable consideration is generally constrained if it is probable that a significant reversal in the amount of cumulative revenue recognized will occur when the uncertainty associated with the variable consideration is subsequently resolved. Recognition of revenue Drilling services are consumed as the services are performed and generally enhance a well site which the customer/operator controls. Work performed on a well site does not create an asset with an alternative use to the contractor since the well/asset being worked on is owned by the customer. Therefore, the Company’s measure of progress for a drilling contract is hours available to drill over the contracted duration. This unit of measure is representative of an output method as described in ASC 606. The following chart details the types of fees found in a typical drilling contract and the related recognition method under ASC 606: Fee type Revenue Recognition Day rate Recognition is based on the day rates earned/invoiced as it relates to the level of service provided for each fractional-hour throughout the contract. Mobilization and upgrade/modification Revenue (both lump-sum and day rate amounts) is estimated at contract inception and included in the transaction price to be recognized over the expected recognition period. Demobilization Unconstrained demobilization revenue (both lump-sum and day rate amounts) is estimated at contract inception, included in the transaction price, and recognized over the expected recognition period in proportion to the passage of each hour available to drill. Bonuses and penalty Unconstrained bonus and/or penalty revenue is estimated at contract inception and included in the transaction price. Amounts are recognized in the period corresponding to the distinct hourly increment(s) of service provided (i.e. the specific period which the bonus or penalty relates to). Reimbursement Recognized (gross of costs incurred), at the point the product or service is consumed, and in the amount billed to the customer. Future performance obligation and financing arrangements Due to the recognition of day rate, as described above, the Company's primary future promised service relates to unconstrained demobilization. Under ASC 606 the Company recognizes unconstrained demobilization revenue over the life of the contract whereas in a typical drilling contract the demobilization, and the resulting cash payment for demobilization, does not occur until the end of the contract. At September 30, 2018 , the Company had a contract asset of $5.3 million for unconstrained demobilization revenue (see Note 2 ) related to the Company recognizing $5.3 million in unconstrained demobilization revenue into income during the three and nine months ended September 30, 2018 . We expect to recognize the remaining $3.2 million of our total estimated $8.5 million of unconstrained demobilization into revenue during the remainder of 2018 and 2019 in the amount of $1.5 million and $1.7 million , respectively. We have applied the optional exemption afforded in ASU No. 2014-09 and have not disclosed the variable consideration related to the estimated future day rate revenues. Upon adoption of this standard as of January 1, 2018, the Company recognized a $5.5 million increase to retained earnings related to unconstrained demobilization provisions. Subsequently, during the first quarter of 2018, the Company received a $5.5 million cash payment for such demobilization related to one of the Company's contracts. Under ASC 606, a significant financing component may exist, regardless of whether the promise is explicitly stated or implied by the payment terms stipulated in a contract, where there is a separation between the timing of services provided and the timing of payment in contracts with terms exceeding one year. Generally, a typical drilling contract stipulates for billings on a monthly basis and payment terms vary by contract and customer but are customarily paid within 90 days. It is rare for a drilling contract to explicitly address a financing component and payments of up-front fees correspond to cash outlays which Rowan must undertake in order to complete a given drilling contract. Recently Adopted Accounting Pronouncements - In addition to Revenue from Contracts with Customers (ASC 606) (see "Revenue Recognition" above), the Company has recently adopted the following accounting pronouncements: Statement of Cash Flows - In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (ASC 230): Classification of Certain Cash Receipts and Cash Payments, which provides guidance on eight cash flow classification issues with the objective of reducing differences in practice. As of January 1, 2018, the Company adopted this guidance on a retrospective basis with no material impact on its condensed consolidated financial statements. Statement of Cash Flows Restricted Cash - In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (ASC 230): Restricted Cash , which requires restricted cash to be presented with cash and cash equivalents in the statement of cash flows. The changes in restricted cash and restricted cash equivalents during the period should be included in the beginning and ending cash and cash equivalents balance reconciliation on the statement of cash flows. When cash, cash equivalents, restricted cash or restricted cash equivalents are presented in more than one line item within the statement of financial position, an entity shall calculate a total cash amount in a narrative or tabular format that agrees with the amount shown on the statement of cash flows. Details on the nature and amounts of restricted cash should also be disclosed. As of January 1, 2018, the Company adopted this guidance on a retrospective basis with no impact on its condensed consolidated financial statements. Other Income - In February 2017, the FASB issued ASU No. 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (“ASU 2017-05”), which clarifies the scope of the original guidance within Subtopic 610-20 that was issued in connection with ASU 2014-09, which provides guidance for recognizing gains and losses from the transfer of nonfinancial assets in contracts with non-customers. ASU 2017-05 also adds guidance for partial sales of nonfinancial assets. As of January 1, 2018, the Company adopted this guidance on a modified retrospective basis concurrently with ASC 606. This adoption had no impact on the Company's condensed consolidated financial statements. Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost - In March 2017, the FASB issued ASU No. 2017-07, Compensation - Retirement Benefits (ASC 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, which requires entities to present the service cost component of the net periodic benefit cost in the same income statement line item as other employee compensation costs. The other components of net benefit cost, including interest cost, expected return on plan assets, amortization of prior service cost/credit and actuarial gain/loss, and settlement and curtailment effects, are to be presented outside of any subtotal of operating income. Entities will have to disclose the line(s) used to present the other components of net periodic benefit cost, if the components are not presented separately in the income statement . The ASU also allows only the service cost component to be eligible for capitalization. As of January 1, 2018, the Company adopted this guidance on a retrospective basis with no material impact on its condensed consolidated financial statements. Accumulated Other Comprehensive Income – In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (ASC 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , which allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017. As permitted under this ASU, the Company elected early adoption of this ASU as of January 1, 2018 and recorded a $45.6 million increase to Retained earnings as a reclassification from Accumulated other comprehensive income. The stranded tax effects are for the U.S. income tax rate reduction recognized in the Consolidated Statements of Operations for the year ended December 31, 2017 for the deferred tax asset associated with employee benefit plans. New Accounting Pronouncements - to be adopted Lease Accounting – In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842) : Amendments to the FASB ASC, which requires an entity to recognize lease assets and lease liabilities on the balance sheet and to disclose key qualitative and quantitative information about the entity's leasing arrangements. Based on the original guidance, lessees and lessors would have been required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach, including a number of optional practical expedients that entities may elect to apply. In July 2018, the FASB issued ASU No. 2018-11, Leases (ASC 842): Targeted Improvements , which provides entities with an option to apply the guidance prospectively, instead of retrospectively, and allows for other classification provisions, as described below. ASC 842 is effective for annual and interim periods beginning after December 15, 2018. The Company will elect to recognize its lease asset and lease liabilities on a prospective basis, beginning on January 1, 2019. Prior to the issuance of ASU No. 2018-11, the Company preliminarily determined that its drilling contracts contained a lease component, and the adoption would require the Company to separately recognize revenue associated with the lease and services components. In July 2018, the FASB issued ASU No. 2018-11, which provides a practical expedient that allows entities to combine lease and non-lease components where the revenue recognition pattern is the same and where the lease component, when accounted for separately, would be considered an operating lease. With respect to the applicability of this practical expedient to the drilling industry, the Company continues to evaluate ASU No. 2018-11 and is working with its peers in the International Association of Drilling Contractors Accounting Sub-committee to discuss the applicability of this practical expedient to its drilling contracts. The adoption of ASC 842 will have an impact on how the Company's consolidated balance sheets, statements of operations, and disclosures contained in its notes to consolidated financial statements will be presented; however, because the Company continues to evaluate the impact of ASU No. 2018-11, it is unable to quantify the overall impact at this time. As a lessee, estimated future minimum lease commitments are approximately $30 million with an estimated present value of approximately $25 million based on the Company's currently identified lease portfolio. The Company will continue to refine its estimate, which is subject to change at the adoption date of ASC 842. Financial Instruments – In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (ASC 326): Measurement of Credit Losses on Financial Instruments, which amends the FASB's guidance on the impairment of financial instruments. The ASU adds to US GAAP an impairment model that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes as an allowance its estimate of expected credit losses. The Company will be required to adopt the amended guidance in annual and interim reports beginning January 1, 2020, with early adoption permitted for fiscal years beginning after December 15, 2018. The Company is in the process of evaluating the impact this amendment will have on its consolidated financial statements . Fair Value Measurement - In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (ASC 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which removes, modifies and adds certain disclosure requirements on fair value measurements including (i) removal of the requirements to disclose the amounts and reasons for as well as the policy for timing of transfers between Level 1 and Level 2 as well as descriptions of valuation processes used for for Level 3 fair value measurements; (ii) certain modifications including clarification that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurement as of the reporting date and; (iii) add disclosures related to changes in unrealized gains and losses for the period included in other comprehensive income (loss) for recurring Level 3 fair value measurements held at the end of the reporting period as well as disclosures for the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The Company will be required to adopt the amended guidance in annual and interim reports beginning January 1, 2020, with early adoption permitted. Adoption is required to be applied prospectively with respect to the amendments on changes in unrealized gains and losses, range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements and narrative description of measurement uncertainty. All other amendments are to be applied retrospectively to all periods presented. The Company is in the process of evaluating the impact this amendment will have on its consolidated financial statements . Defined Benefit Plans - In August 2018, the FASB issued ASU No. 2018-14, Compensation – Retirement Benefits – Defined Benefit Plans – General (Subtopic 715-20): Disclosure Framework – Changes to the Disclosure Requirements for Defined Benefit Plans, which modifies the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The Company will be required to adopt the amended guidance in annual and interim reports beginning January 1, 2021, with early adoption permitted. Adoption is required to be applied on a retrospective basis to all periods presented. The Company is in the process of evaluating the impact this amendment will have on its consolidated financial statements . Internal Use Software - In August 2018, the FASB issued ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force), which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The Company will be required to adopt the amended guidance in annual and interim reports beginning January 1, 2020, with early adoption permitted. Adoption may be applied retrospectively or prospectively to implementation costs incurred after the date of adoption. The Company is in the process of evaluating the impact this amendment will have on its consolidated financial statements .

Contract Assets and Contract Li

Contract Assets and Contract Liabilities	9 Months Ended
	Sep. 30, 2018
Contract with Customer, Asset and Liability [Abstract]
Contract Assets and Contract Liabilities	Contract Assets, Deferred Contract Costs Asset and Contract Liabilities Costs incurred for mobilization, upfront modifications/upgrades and contract preparation are direct costs incurred to fulfill contracts and are expensed over the expected recognition period in the event they are deemed recoverable or in the case of capital upgrades or capital modifications such costs are capitalized and depreciated in accordance with the Company's fixed asset capitalization policy. Such costs other than those capitalized as fixed assets are deferred and recorded as deferred contract costs. Demobilization contract assets reflect the amount of unconstrained demobilization revenue recognized for which the Company's entitlement to invoice the customer is dependent on future performance. The following table sets forth deferred contract costs, demobilization contract assets and deferred revenue on the Condensed Consolidated Balance Sheets (in millions): Balance Sheet Classification September 30, 2018 December 31, 2017 Deferred Contract Costs and Demobilization Contract Assets Current Prepaid expenses and other current assets $ 6.7 $ 2.8 Noncurrent Other assets 0.4 — $ 7.1 $ 2.8 Deferred Revenue - Contract liabilities Current Deferred revenue $ 17.8 $ 1.1 Noncurrent Other liabilities 20.2 0.5 $ 38.0 $ 1.6 Presented in the table below are the changes in deferred contract costs during the nine months ended September 30, 2018 (in millions): September 30, 2018 Deferred Contract Costs Asset Beginning balance $ 2.8 Plus: contractual additions 4.8 Less: amortization 5.8 Ending balance $ 1.8 Presented in the table below are the changes in contract assets (See Note 1 ) during the nine months ended September 30, 2018 (in millions): September 30, 2018 Contract Assets - Demobilization Beginning balance $ — Plus: contractual additions 5.3 Ending balance $ 5.3 Presented in the table below are the changes in deferred revenue during the nine months ended September 30, 2018 (in millions): September 30, 2018 Deferred Revenue - Deferred mobilization and upgrade/modification revenue Beginning balance $ 1.6 Plus: contractual additions (1) 45.5 Less: amortization 9.1 Ending balance $ 38.0 (1) Includes $28.6 million of deferred revenue related to capital expenditures for the Bess Brants , Earnest Dees , EXL I and EXL IV (all leased to ARO) to be received as reimbursement from ARO. A receivable of $28.6 million is included in Receivables - trade and other on the Condensed Consolidated Balance Sheet at September 30, 2018. Estimated future amortization at September 30, 2018 of our deferred revenue and deferred contract costs to be recognized over the expected recognition period is set forth in the following table (in millions): Remaining 2018 2019 2020 2021 Total Amortization of deferred revenue $ 6.2 $ 13.9 $ 9.6 $ 8.3 $ 38.0 Amortization of deferred contract costs 0.9 0.6 0.2 0.1 1.8 No impairment losses were recognized on contract assets during the three and nine months ended September 30, 2018 . Customer Contract Amendment (Cobalt) - Deferred Revenue – During the three and nine months ended September 30, 2017 , the Company amortized $28.9 million and $57.5 million , respectively, of the $95.9 million of revenue deferred in 2016 related to a contract amendment to our subsidiary's drilling contract with Cobalt with respect to the drillship Rowan Reliance (the "Cobalt Contract"). The Cobalt Contract was originally scheduled to conclude on February 1, 2018, and the amendment provided for termination of the Cobalt Contract as early as March 31, 2017 in consideration for a lump sum payment of $95.9 million . As the Company had the obligation and intent to have the drillship or a substitute available through the pre-amended contract scheduled end date, in certain circumstances (including a 90 day notice of intent to use the rig prior to the original contract scheduled end date of February 1, 2018), the $95.9 million settlement was recorded in 2016 as a deferred revenue liability with an amortization period beginning April 1, 2017 and extending no further than the pre-amended contract scheduled end date. The deferred revenue liability was fully amortized as of December 31, 2017 as Cobalt did not provide notice to the Company by November 2, 2017 (90 day notice of intent to use the rig).

Equity Method Investments and V

Equity Method Investments and Variable Interest Entities	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Joint Ventures Disclosure [Text Block]	Equity Method Investments and Variable Interest Entities On November 21, 2016, Rowan and Saudi Aramco, through their subsidiaries, entered into a Shareholders’ Agreement to create a 50 / 50 joint venture, known as ARO. ARO commenced operations on October 17, 2017, and owns, manages and operates offshore drilling units in Saudi Arabia. See Note 1 for additional information related to ARO. The Company accounts for its interest in ARO using the equity method of accounting and only recognizes its portion of equity earnings in the Company's condensed consolidated financial statements. ARO is a variable interest entity; however, the Company is not the primary beneficiary and therefore does not consolidate ARO. The Company's judgment regarding the level of influence over ARO included considering key factors such as: each company's ownership interest, representation on the board of managers of ARO, ability to direct activities that most significantly impact ARO's economic performance, as well as the ability to influence policy-making decisions. Summarized financial information Summarized financial information for ARO, as derived from ARO's financial statements, is as follows (in millions): Three months ended September 30, 2018 Nine months ended September 30, 2018 Revenue $ 89.2 $ 218.3 Direct operating costs (excluding items below) 51.2 120.5 Depreciation and amortization 17.0 50.4 Selling, general and administrative 6.8 20.0 Gain on disposals of property and equipment (1.0 ) — Income from operations 15.2 27.4 Interest expense (5.7 ) (16.9 ) Provision for income taxes 3.2 3.6 Net income $ 6.3 $ 6.9 Rowan's equity in earnings from ARO $ 3.1 $ 3.4 September 30, 2018 December 31, 2017 Current assets $ 205.8 $ 108.6 Non-current assets 468.8 459.7 Total assets $ 674.6 $ 568.3 Current liabilities $ 107.4 $ 29.2 Non-current liabilities 566.3 545.1 Total liabilities $ 673.7 $ 574.3 Related party transactions In connection with the establishment of ARO the Company signed an Asset Transfer and Contribution Agreement. As part of this agreement the Company contributed cash to ARO of $357.7 million in exchange for a 10-year shareholder note receivable from ARO, initially totaling $357.7 million , at a stated interest rate of LIBOR plus two percent . As of September 30, 2018 , and December 31, 2017 , the outstanding amount for this shareholder note receivable was $269.0 million and $271.3 million , consisting of $269.0 million and $270.2 million , respectively, included in Long-term note receivable from unconsolidated subsidiary on the Company's Condensed Consolidated Balance Sheets. In addition, at December 31, 2017, the Company had a current portion of shareholder note receivable of $1.1 million , which was included in Receivables - trade and other on the Company's Condensed Consolidated Balance Sheets. Interest related to this note is being recognized as a part of Interest income in the Company's Condensed Consolidated Statements of Operations and totaled approximately $2.8 million and $8.4 million for the three and nine months ended September 30, 2018 , respectively. At September 30, 2018 , the Company had an interest receivable from ARO of $7.5 million which is included in Prepaid expenses and other current assets on the Condensed Consolidated Balance Sheet. In conjunction with the establishment of ARO, the Company entered into a series of agreements with ARO including: a Transition Services Agreement, Secondment Agreement and Lease Agreements. Pursuant to these agreements, the Company, or its seconded employees, will provide various services to ARO, and in return, the Company is to be provided remuneration for those services. From time to time Rowan may sell equipment or supplies to ARO. Revenue and other amounts recognized by Rowan related to these agreements and transactions is as follows (in millions): Three months ended September 30, 2018 Nine months ended September 30, 2018 Secondment Revenue - Jack-ups $ 14.4 $ 36.2 Lease Revenue - Jack-ups 8.0 9.1 Transition Services Revenue - Unallocated 9.0 26.9 Sales of supplies - Jack-ups 2.0 3.9 Total Revenue received from ARO $ 33.4 $ 76.1 Proceeds from equipment sales to ARO (a) $ 5.9 $ 7.6 (a) A gain of $0.9 million and $0.7 million for the three and nine months ended September 30, 2018, respectively, was recognized in Loss on disposals of property and equipment on the Condensed Consolidated Statements of Operations. $6.8 million is included in Receivables - trade and other as of September 30, 2018 for the $7.6 million purchase price proceeds. Total accounts receivable from ARO totaled approximately $59.5 million and $17.3 million as of September 30, 2018 and December 31, 2017 , respectively, and are included in Receivables - trade and other on the Condensed Consolidated Balance Sheets. The Company also entered into a Rig Management Agreement pursuant to which ARO provides certain rig management services for Rowan's rigs while they are contracted with Saudi Aramco and the Company compensates ARO for the services in which they provide to Rowan. For the three and nine months ended September 30, 2018 , the Company recognized $9.2 million and $31.8 million , respectively, in Direct operating cost in the Condensed Consolidated Statements of Operations related to these rig management services. Additionally, ARO may sell equipment or supplies to Rowan or purchase such for Rowan, in which case ARO is provided reimbursement. For the three and nine months ended September 30, 2018 , the Company recognized $4.4 million and $10.1 million , respectively, in Direct operating cost in the Condensed Consolidated Statements of Operations related to these transactions. Accounts payable to ARO totaled approximately $11.3 million and $10.8 million as of September 30, 2018 and December 31, 2017 , respectively. The following summarizes the total assets and liabilities as reflected in the Company's Condensed Consolidated Balance Sheets as well as the Company's maximum exposure to loss related to ARO (in millions). Generally, the Company's maximum exposure to loss is limited to its 1) equity investment in the joint venture, 2) outstanding note receivable and 3) any amounts receivable by the Company for services it provides to the joint venture, reduced by payables for services which the Company owes to ARO. September 30, 2018 December 31, 2017 Total assets $ 370.3 $ 319.5 Total liabilities 11.3 10.8 Maximum exposure to loss $ 359.0 $ 308.7

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic income (loss) per share is computed by dividing net income (loss) available to common shareholders by the weighted-average number of common shares outstanding during the period. Diluted income per share includes the additional weighted effect of dilutive securities outstanding during the period, which includes RSUs, P-Units, share options and SARs granted under share-based compensation plans. The effect of share equivalents is not included in the computation for periods in which a net loss occurs because to do so would be anti-dilutive. Share options, SARs, P-Units and RSUs granted under share-based compensation plans are anti-dilutive and excluded from diluted earnings per share when the hypothetical number of shares that could be repurchased under the treasury stock method exceeds the number of shares that can be exercised, or when the Company reports a net loss from continuing operations. Anti-dilutive shares, which could potentially dilute earnings per share in the future, are set forth below (in millions): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Share options and appreciation rights 1.5 1.7 1.5 1.7 P-Units and RSUs 4.0 4.0 4.2 3.9 Total potentially dilutive shares 5.5 5.7 5.7 5.6

Pension and Other Postretiremen

Pension and Other Postretirement Benefits	9 Months Ended
	Sep. 30, 2018
Retirement Benefits [Abstract]
Pension and Other Postretirement Benefits	Pension and Other Postretirement Benefits The Company provides defined-benefit pension, health care and life insurance benefits upon retirement for certain full-time employees. The components of net periodic pension cost were as follows (in millions): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Service cost (1) $ 0.4 $ 1.2 $ 5.7 $ 9.2 Interest cost (2) 7.3 6.4 20.7 19.1 Expected return on plan assets (2) (9.2 ) (9.3 ) (27.3 ) (28.2 ) Amortization of net loss (2) 2.4 5.9 16.1 17.4 Amortization of prior service credit (2) (0.1 ) (1.3 ) (1.7 ) (3.8 ) Curtailment gain (2) — — (11.4 ) — Net periodic pension cost $ 0.8 $ 2.9 $ 2.1 $ 13.7 (1) Included in Direct operating costs and Selling, general and administrative on the Condensed Consolidated Statements of Operations (2) Included in Other - net on the Condensed Consolidated Statements of Operations The components of net periodic cost of other postretirement benefits were as follows (in millions): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Service cost (1) $ — $ — $ — $ 0.1 Interest cost (2) 0.1 0.2 0.4 0.7 Amortization of net loss (2) 0.2 0.2 0.6 0.5 Amortization of prior service credit (2) (3.3 ) (3.3 ) (9.9 ) (9.9 ) Total other postretirement benefit cost $ (3.0 ) $ (2.9 ) $ (8.9 ) $ (8.6 ) (1) Included in Direct operating costs and Selling, general and administrative on the Condensed Consolidated Statements of Operations (2) Included in Other - net on the Condensed Consolidated Statements of Operations Over the past 10 years, there have been various changes to our pension plan which have significantly reduced participant benefits under such plan. Further, on May 11, 2018, the Company communicated changes to the participants in its pension plan, that will "freeze" this plan going forward. Based on these changes, effective as of June 30, 2018, eligible participants will no longer receive pay credits and newly hired employees will not be eligible to participate in the pension plan. For the purposes of remeasurement, the Company used the date of April 30, 2018 as it was the month-end date that is closest to May 11, 2018. The impacts of these changes to the plan as of May 11, 2018, are presented in the table below (in millions): Liability increase (decrease) Accumulated other comprehensive income (loss) Deferred tax asset decrease (increase) Income included in Other- net Income tax expense (increase) decrease Plan change to projected benefit obligation $ (1.6 ) $ 1.3 $ 0.3 $ — $ — Remeasurement gain (29.9 ) 23.6 6.3 — — Curtailment — (9.0 ) (1.0 ) 11.4 (1.4 ) Total $ (31.5 ) $ 15.9 $ 5.6 $ 11.4 $ (1.4 ) The Company records unrealized gains and losses related to net periodic pension and other postretirement benefit cost net of estimated taxes in Accumulated other comprehensive income (loss). The Company has a valuation allowance against its net U.S. deferred tax asset that is not expected to be realized. A portion of this valuation allowance is related to deferred tax benefits or expense as recorded in Accumulated other comprehensive income (loss). During the nine months ended September 30, 2018 , the Company contributed $21.3 million to its pension and other postretirement benefit plans and expects to make additional contributions to such plans totaling approximately $5.7 million for the remainder of 2018 .

Commitments and Contingent Liab

Commitments and Contingent Liabilities	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	Commitments and Contingent Liabilities Letters of credit – The Company periodically employs letters of credit in the normal course of its business and had outstanding letters of credit of approximately $7.7 million at September 30, 2018 , of which $5.4 million were issued under the Company's New Credit Facility. Joint venture funding obligations – Each of Rowan and Saudi Aramco have agreed to take all steps necessary to ensure that ARO purchases at least 20 new build jack-up rigs ratably over 10 years once Saudi Aramco's joint venture to manufacture rigs commences operations. The first rig is expected to be delivered as early as 2021. Rowan and Saudi Aramco intend that the newbuild jack-up rigs will be financed out of available cash from operations and/or funds available from third party debt financing. The parties agreed that Saudi Aramco as a customer will provide drilling contracts to ARO in connection with the acquisition of the new rigs, which contracts could be used as security for third party debt financing if needed. If cash from operations or financing is not available to fund the cost of the newbuild jack-up rig, each partner is obligated to contribute funds, in the form of additional shareholder loans, to purchase such rigs, over time of up to a maximum amount of $1.25 billion per partner in the aggregate for all 20 newbuild jack-up rigs, which total investment amount is subject to a reduction formula as rigs are delivered. Further, no shareholder will be required to fund the delivery of more than three rigs during any twelve (12) month period. Uncertain tax positions – The Company has been advised by the IRS of proposed unfavorable tax adjustments of $85 million including applicable penalties for the open tax years 2009 through 2012. The unfavorable tax adjustments primarily related to the following items: 2009 tax benefits recognized as a result of applying the facts of a third-party tax case that provided favorable tax treatment for certain non-U.S. contracts entered into in prior years to the Company’s situation; transfer pricing; and domestic production activity deduction. The Company has protested the proposed adjustment. However, the IRS does not agree with the Company's protest and they have submitted the proposed unfavorable tax adjustments to be reviewed by the IRS appeals group. In years subsequent to 2012, the Company has similar positions that could be subject to adjustments for the open years. The Company has provided for amounts that it believes will be ultimately payable under the proposed adjustments and intends to vigorously defend its positions; however, if the Company determines the provisions for these matters to be inadequate due to new information or the Company is required to pay a significant amount of additional U.S. taxes and applicable penalties and interest in excess of amounts that have been provided for these matters, the Company's consolidated results of operations and cash flows could be materially and adversely affected. The gross unrecognized tax benefits excluding penalties and interest are $98 million and $102 million as of September 30, 2018 and December 31, 2017 , respectively. The decrease to gross unrecognized tax benefits was primarily due to the lapse in a statute of limitations and audit closures, partially offset by adjustments to prior years' tax positions taken in certain jurisdictions, and tax positions taken related to current year-to-date anticipated transfer pricing positions. If the September 30, 2018 , net unrecognized tax benefits excluding penalties and interest were recognized, this would favorably impact the Company's tax provision by $35 million . It is reasonable that the existing liabilities for the unrecognized tax benefits may increase or decrease over the next 12 months as a result of audit closures and statute expirations; however, the ultimate timing of the resolution and/or closure of audits is highly uncertain. Pending or threatened litigation – The Company is involved in various routine legal proceedings incidental to its businesses and vigorously defends its position in all such matters. Although the outcome of such proceedings cannot be predicted with certainty, the Company believes that there are no known contingencies, claims or lawsuits that will have a material adverse effect on its financial position, results of operations or cash flows. In addition to the legal proceedings described above, the Company received a claim in February 2018 by a former agent in the Middle East for compensation associated with the Company's termination of the agent's services. As of September 30, 2018 , this matter has been resolved.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation	Share-Based Compensation On February 27, 2018, the Company granted RSUs to employees for annual incentive awards pursuant to its long-term incentive plan with a grant-date fair value aggregating $16.6 million which will be recognized as compensation expense over a weighted-average period of 2.7 years from the grant date. The awards vest ratably over three years except to the extent they may vest earlier under the Company's retirement policy. Additionally, on February 27, 2018, the Company granted to certain members of management P-Units that have a target value of $100 per unit. The amount ultimately earned is determined by the Company’s absolute TSR performance and relative TSR performance as measured against a group of companies selected by the Company Compensation Committee, over a three -year period ending December 31, 2020. The amount earned could range from zero to $200 per unit depending on the Company's performance. Twenty-five percent of the P-Units’ value is determined by the Company’s absolute TSR performance and relative TSR ranking for each one -year period ended December 31, 2018 , 2019 , and 2020 and 25% of the P-Units’ value is determined by the Company's absolute TSR performance and relative TSR ranking for the three -year period ended December 31, 2020. P-Units cliff vest and payment is made, if any, on the third anniversary following the grant date. Any employee who terminates employment with the Company prior to the third anniversary for any reason other than retirement will not receive any payment with respect to P-Units unless approved by the Company Compensation Committee. Settlement of the P-Units granted may be in cash, shares or a combination thereof, at the Company Compensation Committee's discretion. The grant date fair value of P-Units granted on February 27, 2018 was estimated to be $6.4 million . Fair value for P-units are estimated using the Monte Carlo simulation model, which considers the probabilities of the Company’s relative TSR performance and TSR ranking at the end of each performance period, and the amount of the payout at each rank to determine the probability-weighted expected payout. The Company uses liability accounting to account for the P-Units. Compensation is generally recognized on a straight-line basis over a maximum period of three years from the grant date and is adjusted for changes in fair value through the end of the performance period. The Company recognizes compensation cost on the accelerated method for those retirement eligible or who will become retirement eligible during the vesting period as the awards provide for pro-rata vesting rather than full vesting if a retirement eligible employee retires prior to the end of the 36 month service period. Liabilities for estimated P-Unit obligations at September 30, 2018 , for 2018 grants and prior, included $8.5 million and $5.8 million classified as current and noncurrent, respectively, compared to $11.5 million and $10.5 million , respectively, at December 31, 2017 . Current and noncurrent estimated P-Unit liabilities are included in Accrued liabilities, and Other liabilities, respectively, in the Condensed Consolidated Balance Sheets. At September 30, 2018 , estimated unrecognized compensation cost related to nonvested share-based compensation arrangements totaled approximately $36.4 million , which is expected to be recognized as compensation expense over a remaining weighted-average period of 1.8 years .

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The fair value hierarchy prescribed by US GAAP requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The three levels of inputs that may be used to measure fair value are: • Level 1 – Quoted prices for identical instruments in active markets; • Level 2 – Quoted market prices for similar instruments in active markets; quoted prices for identical instruments in markets that are not active, and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets; and • Level 3 – Valuations derived from valuation techniques in which one or more significant inputs or significant value drivers are unobservable, such as those used in pricing models or discounted cash flow methodologies, for example. The applicable level within the fair value hierarchy is the lowest level of any input that is significant to the fair value measurement. Assets and Liabilities Measured at Fair Value on a Recurring Basis Assets measured at fair value on a recurring basis are presented below (in millions): Estimated fair value measurements Fair value Quoted prices in active markets (Level 1) Significant other observable inputs (Level 2) Significant other unobservable inputs (Level 3) September 30, 2018: Assets - cash equivalents $ 1,015.7 $ 1,015.7 $ — $ — Other assets (Egyptian Pounds) 1.4 1.4 — — Other assets (Angolan Kwanza) 2.5 2.5 — — December 31, 2017: Assets - cash equivalents $ 1,332.1 $ 1,332.1 $ — $ — Other assets (Egyptian Pounds) 2.2 2.2 — — Other assets (Angolan Kwanza) 4.3 4.3 — — At September 30, 2018 , and December 31, 2017 , the Company held Egyptian pounds in the amount of $1.4 million and $2.2 million , respectively, which are classified as Other assets on the Condensed Consolidated Balance Sheets. The Company ceased drilling operations in Egypt in 2014, and is currently working to obtain access to the funds for use outside Egypt to the extent they are not utilized. Given stricter foreign currency exchange controls in Angola, the Company determined in May 2017 that its previous method of converting Angola Kwanza to USD is likely no longer feasible. As a result, at September 30, 2018 and December 31, 2017 , the Company classified its Angolan Kwanza USD equivalent balance of $2.5 million and $4.3 million , respectively, as non-current assets in Other assets on the Condensed Consolidated Balance Sheets. Currently, the Company considers the amounts to be recoverable and will continue to evaluate options to convert the Angolan Kwanza to USD. Trade receivables and trade payables, which are required to be measured at fair value, have carrying values that approximate their fair values due to their short maturities. Other Fair Value Measurements Financial instruments not required to be measured at fair value consist of the Company’s publicly traded debt securities. The Company’s publicly traded debt securities had a carrying value of $2.511 billion at September 30, 2018 , and an estimated fair value at that date aggregating $2.250 billion , compared to a carrying and fair value of $2.510 billion and $2.262 billion , respectively, at December 31, 2017 . Fair values of the Company's publicly traded debt securities were provided by a broker who makes a market in such securities and were measured using a market-approach valuation technique, which is a Level 2 fair value measurement. Concentrations of Credit Risk The Company invests its excess cash primarily in time deposits and high-quality money market accounts at several large commercial banks with strong credit ratings, and therefore believes that its risk of loss is minimal. The Company’s customers largely consist of major international oil companies, national oil companies and large investment-grade exploration and production companies. The Company routinely evaluates and monitors the credit quality of potential and current customers. The Company maintains reserves for credit losses when necessary and actual losses have been within management's expectations. Revenue and receivables from transactions with external customers that amount to 10% or more of revenue during the nine months ended September 30 are set forth below: Percentage of revenue from major customers: Nine months ended September 30, Customer Segment 2018 2017 Saudi Aramco Jack-ups 34 % 29 % Anadarko Deepwater 18 % 16 % ARO Drilling Jack-ups and Unallocated and other 12 % — % Shell Jack-ups 6 % — % Cobalt International Deepwater — % 14 % Percentage of receivables from major customers: Customer Segment September 30, 2018 December 31, 2017 Saudi Aramco Jack-ups 43 % 34 % Anadarko Deepwater — % 19 % ARO Drilling (1) Jack-ups and Unallocated and other 23 % 9 % Shell Jack-ups 12 % — % Cobalt International Deepwater — % — % (1) Includes receivables related to the services provided to ARO (see Note 3 ).

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Shareholders' Equity	Shareholders' Equity Reclassifications from Accumulated Other Comprehensive Loss – The following table sets forth the significant amounts reclassified out of each component of accumulated other comprehensive loss and their effect on net income (loss) for the period (in millions): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Amounts recognized as a component of net periodic pension and other postretirement benefit cost: Amortization of net loss $ (2.6 ) $ (6.1 ) $ (16.7 ) $ (17.9 ) Amortization of prior service credit 3.4 4.6 11.6 13.7 Total before income taxes 0.8 (1.5 ) (5.1 ) (4.2 ) Income tax (expense) benefit (0.1 ) 0.5 1.1 1.5 Total reclassifications for the period, net of income taxes $ 0.7 $ (1.0 ) $ (4.0 ) $ (2.7 ) The Company records unrealized gains and losses related to net periodic pension and other postretirement benefit cost net of estimated taxes in Accumulated other comprehensive income (loss). The Company has a valuation allowance against its net U.S. deferred tax asset that is not expected to be realized. A portion of this valuation allowance is related to deferred tax benefits or expense as recorded in Accumulated other comprehensive income (loss).

Other Financial Statement Discl

Other Financial Statement Disclosures	9 Months Ended
	Sep. 30, 2018
Other Financial Statement Disclosures [Abstract]
Other Financial Statement Disclosures	Other Financial Statement Disclosures Accounts Receivable – The following table sets forth the components of Receivables - trade and other (in millions): September 30, 2018 December 31, 2017 Trade $ 260.1 $ 195.8 Income tax 15.1 8.0 Other 6.3 9.0 Total Receivables - trade and other $ 281.5 $ 212.8 Accrued Liabilities – The following table sets forth the components of Accrued liabilities (in millions): September 30, 2018 December 31, 2017 Pension and other postretirement benefits $ 10.3 $ 27.0 Compensation and related employee costs 41.2 69.0 Interest 39.6 32.0 Income taxes 13.5 15.4 Other 17.6 15.7 Total Accrued liabilities $ 122.2 $ 159.1 Long-term Debt – Long-term debt consisted of the following (in millions): September 30, 2018 December 31, 2017 7.875% Senior Notes, due August 2019 ($201.4 million principal amount; 8.0% effective rate) $ 201.1 $ 200.9 4.875% Senior Notes, due June 2022 ($620.8 million principal amount; 4.7% effective rate) 624.0 624.6 4.75% Senior Notes, due January 2024 ($398.1 million principal amount; 4.8% effective rate) 396.2 395.9 7.375% Senior Notes, due June 2025 ($500 million principal amount; 7.4% effective rate) 497.8 497.5 5.4% Senior Notes, due December 2042 ($400 million principal amount; 5.4% effective rate) 395.2 395.1 5.85% Senior Notes, due January 2044 ($400 million principal amount; 5.9% effective rate) 396.4 396.3 Total carrying value $ 2,510.7 $ 2,510.3 Current portion (1) 201.1 — Carrying value, less current portion $ 2,309.6 $ 2,510.3 (1) Current portion of long-term debt at September 30, 2018 included the 7.875% Senior Notes due in August 2019. Credit Facility On May 22, 2018, the Company amended and restated its Existing Credit Agreement, which permitted, among other things, entry into the New Credit Agreement and a non-pro rata commitment reduction (the "Commitment Reduction") for each lender under the Existing Credit Agreement who became a lender under the New Credit Facility. The Existing Credit Agreement further provided for, among other things; (i) the reduction of the Existing Credit Agreement's letter of credit subfacility to $0 , (ii) the Commitment Reduction and (iii) the resignation of Wells Fargo as administrative agent and appointment of Wilmington Trust, National Association, as successor administrative agent under the Existing Credit Agreement. The Commitment Reduction resulted in the lenders under the New Credit Facility having no commitments under the Existing Credit Facility and reduced the aggregate principal amount of commitments under the Existing Credit Facility to $310.7 million . Of the $310.7 million of availability under the Existing Credit Facility, $60.0 million of the availability matures on January 23, 2019, $150.7 million of the availability matures on January 23, 2020, and the remaining $100.0 million of the availability matures on January 23, 2021. Availability under the Existing Credit Facility was $310.7 million at September 30, 2018 as no amounts were drawn. Advances under the Existing Credit Facility bear interest at LIBOR or base rate as specified in the Existing Credit Agreement plus an applicable margin, which is dependent upon the Company's credit ratings. The applicable margins for LIBOR and base rate advances range from 1.125% - 2.0% and 0.125% - 1.0% , respectively. The Company is also required to pay a commitment fee on undrawn amounts of the Existing Credit Facility, which ranges from 0.125% to 0.35% , depending on the Company's credit ratings. The Existing Credit Facility requires the Company to maintain a total debt-to-capitalization ratio of less than or equal to 60% . The Company's consolidated debt to total capitalization ratio at September 30, 2018 , was 33% . Additionally, the Existing Credit Facility has customary restrictive covenants that, including others, restrict the Company's ability to incur certain debt and liens, enter into certain merger and acquisition agreements, sell, transfer, lease or otherwise dispose of all or substantially all of the Company's assets and substantially change the character of the Company's business from contract drilling. Availability under the New Credit Facility is $955 million , which matures on May 22, 2023, provided; however, that if the Company's 2022 Notes are not refinanced in full on or prior to February 1, 2022, the maturity date will be February 1, 2022. The New Credit Agreement currently provides for a swingline subfacility in the amount of $50 million , and a letter of credit subfacility in the amount of $129 million , with the ability to increase such amounts (subject to certain lenders agreeing to become issuers of letters of credit following the closing date). Borrowings under the New Credit Facility may be used for working capital and other general corporate purposes. The New Credit Agreement also includes restrictions on borrowings if, after giving effect to any such borrowings and the application of the proceeds thereof, the aggregate amount of the Company’s cash-on-hand, subject to certain exceptions, would exceed $200 million . As of September 30, 2018 , no amounts were outstanding and $5.4 million in letters of credit had been issued under the New Credit Facility leaving remaining availability of $949.6 million . Subject to the successful procurement of additional commitments from new or existing lenders, borrower may elect to increase the maximum amount available under the New Credit Facility from $955 million by an additional amount not to exceed $250 million . Revolving borrowings under the New Credit Facility bear interest, at the Company's option, at either (a) the sum of LIBOR plus a margin ranging between 2.75% to 4.25% , depending on the credit rating of the Company, or (b) the sum of a base rate specified in the New Credit Agreement, plus a margin ranging between 1.75% to 3.25% , depending on the credit rating of the Company. The Company is also required to pay a commitment fee on undrawn amounts of the New Credit Agreement, which ranges from 0.375% to 0.7% depending on the Company's credit rating. The New Credit Agreement contains certain financial covenants applicable to the Company, including: (i) a covenant restricting debt to total tangible capitalization to not greater than 55% at the end of each fiscal quarter, (ii) a minimum liquidity requirement of $300 million , (iii) a covenant that the ratio of the net book value of the Company's drilling rigs either marketed or under contract with a customer to the sum of commitments under the New Credit Agreement, the commitments under the Existing Credit Agreement plus any other indebtedness of the borrower and guarantors (other than unsecured intercompany indebtedness that is contractually subordinated to the obligations under the New Credit Agreement) that is secured by a lien, guaranteed by, or has an obligor who is a subsidiary of Rowan plc, in each case, that directly own or operates a drilling rig, is not less than 3:00 to 1:00 at the end of each fiscal quarter (the "Marketed Rig Value Ratio") and (iv) a covenant that the ratio of (A) the net book value of the Company's drilling rigs, subject to certain exclusions, that are directly wholly owned by Rowan plc and its subsidiaries who are borrowers or guarantors under the New Credit Facility to (B) the net book value of all drilling rigs owned by the Company and certain of its local content affiliates, is not less than 80% at the end of each fiscal quarter (the "Guaranteed Rig Value Ratio"). As of September 30, 2018 , the Company was in compliance with each of the financial covenants under the New Credit Agreement as follows: Min/Max Value as of Financial covenant Requirement September 30, 2018 Total tangible capitalization 55 % 33 % Liquidity (in millions) $ 300.0 $ 2,292.7 Marketed Rig Value Ratio 3.00 4.14 Guaranteed Rig Value Ratio 80 % 84 % The New Credit Agreement also contains additional covenants generally applicable to the Company and its subsidiaries that the Company considers usual and customary for an agreement of this type, including compliance with laws (including environmental laws, ERISA and anti-corruption and sanctions laws), delivery of quarterly and annual financial statements, maintenance and operation of property, restrictions on investments, asset sales, the incurrence of liens and indebtedness, mergers and other fundamental changes, restricted payments, repurchases and redemptions of indebtedness and equity, sale and leaseback transactions and transactions with affiliates. Borrowings under the New Credit Facility are subject to acceleration upon the occurrence of events of default that the Company considers usual and customary for an agreement of this type. Debt Reductions In December 2016, the Company commenced cash tender offers for $750 million aggregate principal amount of the Subject Notes issued by the Company (the "Tender Offers"). The Tender Offers expired on January 3, 2017; however, there was also an early tender expiration on December 16, 2016 which provided for an early tender premium. Subject Notes validly tendered and accepted for purchase prior to the early tender expiration time on December 16, 2016, received tender offer consideration plus an early tender premium. As a result of the Tender Offers, in December 2016, the Company paid $490.5 million to repurchase $463.9 million aggregate principal amount of outstanding Subject Notes, consisting of $265.5 million of the 2017 Notes, $186.7 million of the 2019 Notes, $9.8 million of the 2022 Notes and $1.9 million of the 2024 Notes, and recognized a $33.6 million loss on the early extinguishment of debt which included approximately $5.9 million of bank and legal fees. In January 2017, at the expiration of the Tender Offers, the Company paid $32.8 million to repurchase an additional $34.6 million aggregate principal amount of outstanding Subject Notes, consisting of $0.1 million of the 2017 Notes, $0.9 million of the 2019 Notes and $33.6 million of the 2022 Notes. The Company recognized a $2.0 million gain on the early extinguishment of debt. On January 9, 2017, the Company called for redemption $92.1 million aggregate principal amount of the 2017 Notes that remained outstanding and on February 8, 2017, the Company paid $94.0 million to redeem such notes and recognized a $2.1 million loss on early extinguishment of debt. In the second quarter of 2017, the Company paid $33.5 million in cash to retire $35.8 million aggregate principal amount of the 2022 Notes and recognized a $2.4 million gain on early extinguishment of debt. In July 2017, the Company paid $7.0 million in cash to retire $6.5 million aggregate principal amount of the 2019 Notes and recognized a $0.5 million loss on early extinguishment of debt. Debt Guarantee and Other Provisions The Senior Notes are RCI’s senior unsecured obligations and rank senior in right of payment to all of its subordinated indebtedness and pari passu in right of payment with any of RCI’s future senior indebtedness, including any indebtedness under RCI’s senior Existing Credit Facility. The Senior Notes rank effectively junior to RCI’s future secured indebtedness, if any, to the extent of the value of its assets constituting collateral securing that indebtedness and to all existing and future indebtedness of its subsidiaries (other than indebtedness and liabilities owed to RCI). The Senior Notes are fully and unconditionally guaranteed on a senior and unsecured basis by Rowan plc (see Note 12 ). All or part of the Senior Notes may be redeemed at any time for an amount equal to 100% of the principal amount plus accrued and unpaid interest to the redemption date plus the applicable make-whole premium, if any. The 2025 Notes contain a provision whereby upon a change of control repurchase event, as defined in the indenture governing the 2025 Notes, the Company may be required to make an offer to repurchase all outstanding notes at a price in cash equal to 101% of the aggregate principal amount of the notes repurchased, plus any accrued and unpaid interest to the repurchase date. Otherwise, the 2025 Notes contain substantially the same provisions as the Company’s other Senior Notes. Other provisions of the Company's debt agreements limit the ability of the Company to create liens that secure debt, engage in sale and leaseback transactions, merge or consolidate with another company and, in the event of noncompliance, restrict investment activities and asset purchases and sales, among other things. The Company was in compliance with its debt covenants at September 30, 2018 . Supplemental Cash Flow Information – Accrued capital expenditures, which are excluded from capital expenditures in the Condensed Consolidated Statements of Cash Flows until settlement, totaled $26.5 million and $12.4 million at September 30, 2018 and 2017 , respectively. On January 5, 2018, the Company purchased two 2013 Le Tourneau Super 116E jack-up rigs, the Bess Brants and Earnest Dees, formerly, P-59 and P-60, respectively, which were both delivered new into service in 2013, in a public auction from a subsidiary of Petroleo Brasileiro S.A. (“Petrobras”). The purchase price was $38.5 million per unit, or an aggregate $77.0 million , of which $7.7 million was paid as a deposit in December 2017. The remaining balance of $69.3 million as well as $1.5 million in transaction costs were paid in January 2018. Income Taxes – In accordance with US GAAP for interim reporting, the Company has historically estimated its full-year effective tax rate and applied this rate to ordinary income or loss for the reporting period. The Company has determined that since small changes in estimated ordinary income would result in significant changes in the estimated annual effective tax rate this historical method would not provide reliable results for the three and nine months ended September 30, 2018 . Therefore, a discrete year-to-date method of reporting was used for the three and nine months ended September 30, 2018 . The Company provides for income taxes based upon the tax laws and rates in effect in the countries in which it conducts operations. The amounts of the provisions are impacted by such laws and rates and the availability of deductions, credits and other benefits in each of the various jurisdictions. Overall effective tax rate may, therefore, vary considerably from quarter to quarter and from year to year based on the actual or projected location of operations, levels of income, intercompany gains or losses, and other factors. On December 22, 2017, the U.S. government enacted tax legislation commonly referred to as the U.S. Tax Act. The U.S. Tax Act significantly changed U.S. corporate income tax laws including but not limited to reducing the U.S. corporate income tax rate from 35% to 21% , requiring a one-time transition tax on mandatory deemed repatriation of certain unremitted non-U.S. earnings as of December 31, 2017, and changing how non-U.S. subsidiaries are taxed in the U.S. as of January 1, 2017. The Company is applying the guidance in accordance with the SEC Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act ("SAB 118") that allows provisional estimates for the tax effects of the U.S. Tax Act. As of September 30, 2018 , the Company has adjusted its December 31, 2017 estimate related to the transition tax from $34.1 million to $26.4 million and tax on non-U.S. subsidiaries from $38.3 million to $33.7 million . The Company will fully offset these charges with net operating losses. The December 31, 2017 estimate for remeasurement of U.S. deferred tax assets and liabilities for the income tax rate reduction was adjusted from $56.7 million to $61.6 million . These charges do not impact the financials as they are fully offset by adjustments to a valuation allowance. While the Company was able to make a reasonable estimate of the above items, the ultimate impact may differ from these provisional amounts due to additional analysis and changes in interpretations of existing regulatory guidance. The provisional estimates will be finalized within one year from the date of enactment as allowed under SAB 118. The effective tax rate for the three and nine months ended September 30, 2018 , was (2.5)% and (1.8)% as a result of a tax provision on a pre-tax loss, respectively, compared to 51.0% as a result of a tax benefit on pre-tax loss and (293.7)% as a result of a tax provision on pre-tax loss for the comparable periods ended September 30, 2017 . The Company recognized a tax provision of $3.5 million and $5.8 million for the three and nine months ended September 30, 2018 , respectively, compared to a tax benefit of $21.8 million and a tax provision of $29.3 million for the comparable periods of 2017 . The increase of $25.3 million for the three months ended September 30, 2018 is primarily attributed to the current period estimate using a discrete year-to-date interim reporting method and a reduced benefit from lapses in statute of limitations between 2017 and 2018, partially offset by the impact from the three months ended September 30, 2017 of additional deferred tax expense related to a) restructuring and b) an increase in valuation allowance on Luxembourg deferred tax assets. The decrease of $23.5 million for the nine months ended September 30, 2018 , is primarily attributed to a) the current period estimate using a discrete year-to-date interim reporting method and b) the impact from the nine months ended September 30, 2017 of additional deferred tax expense related to restructuring and an increase in valuation allowance on Luxembourg deferred tax assets, partially offset by c) a reduced benefit from lapses in statute of limitations between 2017 and 2018. The Company has not provided deferred income taxes on certain undistributed earnings of non-U.K. subsidiaries. If facts and circumstances cause a change in expectations regarding future tax consequences, the resulting tax impact could have a material effect on the Company's consolidated financial statements.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Information	Segment Information and Disaggregation of Revenue Prior to ARO commencing operations on October 17, 2017 (see Note 3 ), the Company operated in two segments: Deepwater and Jack-ups. The Company now operates in three principal operating segments: Deepwater, which consists of its drillship operations, Jack-ups, which is composed of the Company's jack-up operations and results associated with the Company's arrangements with ARO primarily under the Transition Services Agreement (direct operating costs only), Rig Management Agreement, Rig Lease Agreements and Secondment Agreement (see Note 3 ), and ARO, the Company's 50 / 50 joint venture with Saudi Aramco. ARO was formed to own, manage and operate offshore drilling units in Saudi Arabia. These segments provide one primary service –contract drilling. The Company evaluates performance primarily based on income from operations. Depreciation and amortization and Selling, general and administrative expenses related to the Company's corporate function and other administrative offices have not been allocated to its operating segments for purposes of measuring segment operating income and are included in "Unallocated and other." In addition, revenue and general and administrative costs related to providing transition services to ARO are included in "Unallocated and other" (see Note 3 ). "Other operating items - expense" consists of, to the extent applicable, loss on disposals of property and equipment. Segment results are presented below (in millions): Three months ended September 30, Deepwater Jack-ups ARO Unallocated and other Reportable segments total Eliminations and adjustments Consolidated 2018 Revenue $ 13.9 $ 170.0 $ 89.2 $ 9.0 $ 282.1 $ (89.2 ) $ 192.9 Operating expenses: Direct operating costs (excluding items below) 48.4 133.9 51.2 — 233.5 (51.2 ) 182.3 Depreciation and amortization 27.3 71.1 17.0 0.6 116.0 (17.0 ) 99.0 Selling, general and administrative — — 6.8 26.6 33.4 (6.8 ) 26.6 Other operating items - (income) expense — 1.5 (1.0 ) — 0.5 1.0 1.5 Equity in earnings of unconsolidated subsidiary — — — — — 3.1 3.1 Income (loss) from operations $ (61.8 ) $ (36.5 ) $ 15.2 $ (18.2 ) $ (101.3 ) $ (12.1 ) $ (113.4 ) 2017 Revenue $ 88.4 $ 203.2 $ — $ — $ 291.6 $ — $ 291.6 Operating expenses: Direct operating costs (excluding items below) 33.2 135.5 — — 168.7 — 168.7 Depreciation and amortization 27.4 75.3 — 0.7 103.4 — 103.4 Selling, general and administrative — — — 24.9 24.9 — 24.9 Other operating items - expense — 2.7 — 0.1 2.8 — 2.8 Income (loss) from operations $ 27.8 $ (10.3 ) $ — $ (25.7 ) $ (8.2 ) $ — $ (8.2 ) Nine months ended September 30, Deepwater Jack-ups ARO Unallocated and other Reportable segments total Eliminations and adjustments Consolidated 2018 Revenue $ 131.8 $ 486.7 $ 218.3 $ 26.9 $ 863.7 $ (218.3 ) $ 645.4 Operating expenses: Direct operating costs (excluding items below) 118.2 397.8 120.5 — 636.5 (120.5 ) 516.0 Depreciation and amortization 81.2 211.3 50.4 1.8 344.7 (50.4 ) 294.3 Selling, general and administrative — — 20.0 77.4 97.4 (20.0 ) 77.4 Other operating items - expense — 5.0 — — 5.0 — 5.0 Equity in earnings of unconsolidated subsidiary — — — — — 3.4 3.4 Income (loss) from operations $ (67.6 ) $ (127.4 ) $ 27.4 $ (52.3 ) $ (219.9 ) $ (24.0 ) $ (243.9 ) 2017 Revenue $ 371.8 $ 614.3 $ — $ — $ 986.1 $ — $ 986.1 Operating expenses: Direct operating costs (excluding items below) 117.1 391.7 — — 508.8 — 508.8 Depreciation and amortization 84.1 217.8 — 2.1 304.0 — 304.0 Selling, general and administrative — — — 71.3 71.3 — 71.3 Other operating items - expense — 9.3 — — 9.3 — 9.3 Income (loss) from operations $ 170.6 $ (4.5 ) $ — $ (73.4 ) $ 92.7 $ — $ 92.7 The classifications of revenue among geographic areas in the tables which follow (in millions) were determined based on segment and physical location of assets. Because the Company evaluates performance primarily based on income from operations and the Company’s offshore drilling rigs are mobile, classifications by area are dependent on the rigs’ location at the time revenue is earned and may vary from one period to the next. Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Deepwater Revenue: United States $ 13.9 $ 88.4 $ 131.8 $ 369.4 Other — — — 2.4 Total $ 13.9 $ 88.4 $ 131.8 $ 371.8 Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Jack-ups Revenue: Saudi Arabia $ 88.8 $ 102.7 $ 270.8 $ 290.2 Norway 2.3 45.8 65.7 140.9 Trinidad 39.8 30.3 83.1 106.3 United Kingdom 28.8 12.7 50.7 41.9 United States 10.3 11.7 16.4 34.9 Other — — — 0.1 Total $ 170.0 $ 203.2 $ 486.7 $ 614.3 Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Unallocated and Other Revenue: Saudi Arabia $ 9.0 $ — $ 26.9 $ — Total $ 9.0 $ — $ 26.9 $ — Revenue from Unallocated and other consists of transition services for ARO. Fees for these related services are recognized as the service is performed and such fees are billed on a monthly basis.

Guarantees of Registered Securi

Guarantees of Registered Securities	9 Months Ended
	Sep. 30, 2018
Condensed Financial Information Disclosure [Abstract]
Guarantees of Registered Securities	Guarantees of Registered Securities Rowan plc and its 100%-owned subsidiary, RCI, have entered into agreements providing for, among other things, the full, unconditional and irrevocable guarantee by Rowan plc of the prompt payment, when due, of any amount owed to the holders of RCI's Senior Notes. The condensed consolidating financial information that follows is presented on the equity method of accounting in accordance with Rule 3-10 of Regulation S-X in connection with Rowan plc’s guarantee of the Senior Notes and reflects the corporate ownership structure as of September 30, 2018 . Financial information for the three and nine months ended September 30, 2017 , has been recast to reflect changes to the corporate ownership structure that occurred in the fourth quarter of 2017 and second quarter of 2018. The Condensed Consolidating Balance Sheets as of December 31, 2017 have been recast to reflect changes to the corporate ownership structure that occurred in the second quarter of 2018 as if the corporate ownership structure was in place at January 1, 2015. In addition, the Condensed Consolidating Statements of Operations and Condensed Consolidating Statements of Other Comprehensive Income (Loss) for the three and nine months ended September 30, 2017 , have been adjusted for the adoption of new accounting standards (see Note 1 for additional information). Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Operations Three months ended September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated REVENUE $ — $ 1.7 $ 192.9 $ (1.7 ) $ 192.9 COSTS AND EXPENSES: Direct operating costs (excluding items below) — — 182.3 — 182.3 Depreciation and amortization — — 99.0 — 99.0 Selling, general and administrative 7.6 — 20.7 (1.7 ) 26.6 (Gain) loss on disposals of property and equipment — (0.7 ) 2.2 — 1.5 Total costs and expenses 7.6 (0.7 ) 304.2 (1.7 ) 309.4 Equity in earnings of unconsolidated subsidiary — — 3.1 — 3.1 INCOME (LOSS) FROM OPERATIONS (7.6 ) 2.4 (108.2 ) — (113.4 ) OTHER INCOME (EXPENSE): Interest expense — (37.3 ) (2.4 ) 0.5 (39.2 ) Interest income — 0.5 8.0 (0.5 ) 8.0 Other - net 5.1 (4.5 ) 3.4 — 4.0 Total other income (expense), net 5.1 (41.3 ) 9.0 — (27.2 ) LOSS BEFORE INCOME TAXES (2.5 ) (38.9 ) (99.2 ) — (140.6 ) Provision (benefit) for income taxes — 3.8 (0.3 ) — 3.5 Equity in earnings (losses) of subsidiaries, net of tax (141.6 ) 39.3 — 102.3 — NET LOSS $ (144.1 ) $ (3.4 ) $ (98.9 ) $ 102.3 $ (144.1 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Operations Three months ended September 30, 2017 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated REVENUE $ — $ 0.6 $ 291.8 $ (0.8 ) $ 291.6 COSTS AND EXPENSES: Direct operating costs (excluding items below) — 0.4 171.5 (3.2 ) 168.7 Depreciation and amortization — 4.4 99.0 — 103.4 Selling, general and administrative 7.0 0.1 15.4 2.4 24.9 (Gain) loss on disposals of property and equipment — (0.1 ) 2.9 — 2.8 Total costs and expenses 7.0 4.8 288.8 (0.8 ) 299.8 INCOME (LOSS) FROM OPERATIONS (7.0 ) (4.2 ) 3.0 — (8.2 ) OTHER INCOME (EXPENSE): Interest expense — (38.5 ) (0.1 ) 0.1 (38.5 ) Interest income — 0.9 2.9 (0.1 ) 3.7 Loss on extinguishment of debt — (0.5 ) — — (0.5 ) Other - net 5.1 (5.0 ) 0.7 — 0.8 Total other income (expense) - net 5.1 (43.1 ) 3.5 — (34.5 ) INCOME (LOSS) BEFORE INCOME TAXES (1.9 ) (47.3 ) 6.5 — (42.7 ) Benefit for income taxes — (0.6 ) (22.2 ) 1.0 (21.8 ) Equity in earnings (losses) of subsidiaries, net of tax (19.0 ) 47.6 — (28.6 ) — NET INCOME (LOSS) $ (20.9 ) $ 0.9 $ 28.7 $ (29.6 ) $ (20.9 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Operations Nine months ended September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated REVENUE $ — $ 3.7 $ 645.4 $ (3.7 ) $ 645.4 COSTS AND EXPENSES: Direct operating costs (excluding items below) — — 516.0 — 516.0 Depreciation and amortization — — 294.3 — 294.3 Selling, general and administrative 20.3 0.5 60.3 (3.7 ) 77.4 (Gain) loss on disposals of property and equipment — (0.1 ) 5.1 — 5.0 Total costs and expenses 20.3 0.4 875.7 (3.7 ) 892.7 Equity in earnings of unconsolidated subsidiary — — 3.4 — 3.4 INCOME (LOSS) FROM OPERATIONS (20.3 ) 3.3 (226.9 ) — (243.9 ) OTHER INCOME (EXPENSE): Interest expense — (113.8 ) (4.2 ) 1.4 (116.6 ) Interest income — 2.5 21.5 (1.4 ) 22.6 Other - net 15.1 (12.3 ) 7.8 — 10.6 Total other income (expense), net 15.1 (123.6 ) 25.1 — (83.4 ) LOSS BEFORE INCOME TAXES (5.2 ) (120.3 ) (201.8 ) — (327.3 ) Provision (benefit) for income taxes — (3.7 ) 9.5 — 5.8 Equity in earnings (losses) of subsidiaries, net of tax (327.9 ) 138.5 — 189.4 — NET INCOME (LOSS) $ (333.1 ) $ 21.9 $ (211.3 ) $ 189.4 $ (333.1 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Operations Nine months ended September 30, 2017 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated REVENUES $ — $ 38.2 $ 986.6 $ (38.7 ) $ 986.1 COSTS AND EXPENSES: Direct operating costs (excluding items below) — 1.2 542.2 (34.6 ) 508.8 Depreciation and amortization — 14.4 289.4 0.2 304.0 Selling, general and administrative 18.8 2.0 54.8 (4.3 ) 71.3 Loss on disposals of property and equipment — 1.6 7.7 — 9.3 Total costs and expenses 18.8 19.2 894.1 (38.7 ) 893.4 INCOME (LOSS) FROM OPERATIONS (18.8 ) 19.0 92.5 — 92.7 OTHER INCOME (EXPENSE): Interest expense — (117.1 ) (0.3 ) 0.4 (117.0 ) Interest income — 2.6 6.7 (0.4 ) 8.9 Gain on extinguishment of debt — 1.7 — — 1.7 Other - net 15.4 (14.6 ) 2.9 — 3.7 Total other income (expense) - net 15.4 (127.4 ) 9.3 — (102.7 ) INCOME (LOSS) BEFORE INCOME TAXES (3.4 ) (108.4 ) 101.8 — (10.0 ) Provision (benefit) for income taxes — (10.8 ) 40.1 29.3 Equity in earnings (losses) of subsidiaries, net of tax (35.9 ) 66.7 — (30.8 ) — NET INCOME (LOSS) $ (39.3 ) $ (30.9 ) $ 61.7 $ (30.8 ) $ (39.3 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Comprehensive Loss Three months ended September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET LOSS $ (144.1 ) $ (3.4 ) $ (98.9 ) $ 102.3 $ (144.1 ) OTHER COMPREHENSIVE LOSS: Net reclassification adjustment for amounts recognized in net loss as a component of net periodic benefit cost, net of income taxes (0.7 ) (0.7 ) — 0.7 (0.7 ) COMPREHENSIVE LOSS $ (144.8 ) $ (4.1 ) $ (98.9 ) $ 103.0 $ (144.8 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Comprehensive Income (Loss) Three months ended September 30, 2017 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET INCOME (LOSS) $ (20.9 ) $ 0.9 $ 28.7 $ (29.6 ) $ (20.9 ) OTHER COMPREHENSIVE INCOME: Net reclassification adjustment for amounts recognized in net income (loss) as a component of net periodic benefit cost, net of income taxes 1.0 1.0 — (1.0 ) 1.0 COMPREHENSIVE INCOME (LOSS) $ (19.9 ) $ 1.9 $ 28.7 $ (30.6 ) $ (19.9 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Comprehensive Income (Loss) Nine months ended September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET INCOME (LOSS) $ (333.1 ) $ 21.9 $ (211.3 ) $ 189.4 $ (333.1 ) OTHER COMPREHENSIVE INCOME: Net changes in pension and other postretirement plan assets and benefit obligations recognized in other comprehensive income, net of income taxes 15.9 15.9 — (15.9 ) 15.9 Net reclassification adjustment for amounts recognized in net income (loss) as a component of net periodic benefit cost, net of income taxes 4.0 4.0 — (4.0 ) 4.0 19.9 19.9 — (19.9 ) 19.9 COMPREHENSIVE INCOME (LOSS) $ (313.2 ) $ 41.8 $ (211.3 ) $ 169.5 $ (313.2 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Comprehensive Income (Loss) Nine months ended September 30, 2017 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET INCOME (LOSS) $ (39.3 ) $ (30.9 ) $ 61.7 $ (30.8 ) $ (39.3 ) OTHER COMPREHENSIVE INCOME: Net reclassification adjustment for amounts recognized in net income (loss) as a component of net periodic benefit cost, net of income taxes 2.7 2.7 — (2.7 ) 2.7 COMPREHENSIVE INCOME (LOSS) $ (36.6 ) $ (28.2 ) $ 61.7 $ (33.5 ) $ (36.6 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Balance Sheets September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated CURRENT ASSETS: Cash and cash equivalents $ 0.1 $ 14.9 $ 1,017.4 $ — $ 1,032.4 Receivables - trade and other — 1.1 280.4 — 281.5 Prepaid expenses and other current assets 0.4 13.6 17.4 — 31.4 Total current assets 0.5 29.6 1,315.2 — 1,345.3 Property and equipment - gross — 255.4 8,749.6 — 9,005.0 Less accumulated depreciation and amortization — 136.5 2,430.4 — 2,566.9 Property and equipment - net — 118.9 6,319.2 — 6,438.1 Investments in consolidated subsidiaries 5,111.6 6,540.1 — (11,651.7 ) — Due from affiliates 0.2 748.9 33.2 (782.3 ) — Long-term note receivable from unconsolidated subsidiary — — 269.0 — 269.0 Investment in unconsolidated subsidiary — — 34.3 — 34.3 Other assets — 33.3 11.4 — 44.7 $ 5,112.3 $ 7,470.8 $ 7,982.3 $ (12,434.0 ) $ 8,131.4 CURRENT LIABILITIES: Current portion of long-term debt $ — $ 201.1 $ — $ — $ 201.1 Accounts payable - trade 0.6 15.9 95.7 — 112.2 Deferred revenue — — 17.8 — 17.8 Accrued liabilities — 78.5 43.7 — 122.2 Total current liabilities 0.6 295.5 157.2 — 453.3 Long-term debt — 2,309.6 — — 2,309.6 Due to affiliates 18.3 31.7 732.3 (782.3 ) — Other liabilities 4.6 222.9 41.1 — 268.6 Deferred income taxes - net — — 11.1 — 11.1 Shareholders' equity 5,088.8 4,611.1 7,040.6 (11,651.7 ) 5,088.8 $ 5,112.3 $ 7,470.8 $ 7,982.3 $ (12,434.0 ) $ 8,131.4 Rowan Companies plc and Subsidiaries Condensed Consolidating Balance Sheets December 31, 2017 (In millions) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated CURRENT ASSETS: Cash and cash equivalents $ 0.2 $ 206.3 $ 1,125.6 $ — $ 1,332.1 Receivables - trade and other — 1.2 211.6 — 212.8 Prepaid expenses and other current assets 0.3 10.7 4.5 — 15.5 Total current assets 0.5 218.2 1,341.7 — 1,560.4 Property and equipment - gross — 241.9 8,592.0 — 8,833.9 Less accumulated depreciation and amortization — 121.4 2,159.8 — 2,281.2 Property and equipment - net — 120.5 6,432.2 — 6,552.7 Investments in consolidated subsidiaries 5,401.1 6,387.1 — (11,788.2 ) — Due from affiliates 0.2 680.0 11.5 (691.7 ) — Long-term note receivable from unconsolidated subsidiary — — 270.2 — 270.2 Investment in unconsolidated subsidiary — — 30.9 — 30.9 Other assets — 36.4 7.7 — 44.1 $ 5,401.8 $ 7,442.2 $ 8,094.2 $ (12,479.9 ) $ 8,458.3 CURRENT LIABILITIES: Accounts payable - trade $ 0.7 $ 12.9 $ 83.6 $ — $ 97.2 Deferred revenue — — 1.1 — 1.1 Accrued liabilities — 95.7 63.4 — 159.1 Total current liabilities 0.7 108.6 148.1 — 257.4 Long-term debt — 2,510.3 — — 2,510.3 Due to affiliates 11.2 11.4 669.1 (691.7 ) — Other liabilities 3.8 261.2 28.6 — 293.6 Deferred income taxes - net — — 10.9 — 10.9 Shareholders' equity 5,386.1 4,550.7 7,237.5 (11,788.2 ) 5,386.1 $ 5,401.8 $ 7,442.2 $ 8,094.2 $ (12,479.9 ) $ 8,458.3 Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Cash Flows Nine months ended September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES $ (4.7 ) $ (139.4 ) $ 31.7 $ — $ (112.4 ) CASH FLOWS FROM INVESTING ACTIVITIES: Capital expenditures — (5.6 ) (111.3 ) — (116.9 ) Purchase of rigs — — (70.8 ) — (70.8 ) Proceeds from disposals of property and equipment — 0.2 7.9 — 8.1 Contributions to consolidated subsidiary for note receivable — (1.9 ) — 1.9 — Investments in consolidated subsidiaries — (5.0 ) — 5.0 — Repayments of note receivable from unconsolidated subsidiary — — 2.3 — 2.3 Net cash used in investing activities — (12.3 ) (171.9 ) 6.9 (177.3 ) CASH FLOWS FROM FINANCING ACTIVITIES: Advances (to) from affiliates 8.5 (39.7 ) 31.2 — — Contributions from issuer — — 5.0 (5.0 ) — Proceeds from borrowings — — 1.9 (1.9 ) — Debt issue costs — — (6.1 ) — (6.1 ) Shares repurchased for tax withholdings on vesting of restricted share units (3.9 ) — — — (3.9 ) Net cash provided by (used in) financing activities 4.6 (39.7 ) 32.0 (6.9 ) (10.0 ) DECREASE IN CASH AND CASH EQUIVALENTS (0.1 ) (191.4 ) (108.2 ) — (299.7 ) CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD 0.2 206.3 1,125.6 — 1,332.1 CASH AND CASH EQUIVALENTS, END OF PERIOD $ 0.1 $ 14.9 $ 1,017.4 $ — $ 1,032.4 Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Cash Flows Nine months ended September 30, 2017 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES $ (6.1 ) $ 22.0 $ 240.1 $ (15.0 ) $ 241.0 CASH FLOWS FROM INVESTING ACTIVITIES: Capital expenditures — (17.9 ) (60.7 ) — (78.6 ) Proceeds from disposals of property and equipment — 0.9 0.6 — 1.5 Investments in consolidated subsidiaries — 70.7 — (70.7 ) — Investment in unconsolidated subsidiary — — (25.0 ) — (25.0 ) Net cash provided by (used in) investing activities — 53.7 (85.1 ) (70.7 ) (102.1 ) CASH FLOWS FROM FINANCING ACTIVITIES: Advances (to) from affiliates 7.1 (162.2 ) 155.1 — — Distribution to issuer — — (70.7 ) 70.7 — Reductions of long-term debt — (170.0 ) — — (170.0 ) Shares repurchased for tax withholdings on vesting of restricted share units (4.4 ) — — — (4.4 ) Dividends paid — — (15.0 ) 15.0 — Net cash provided by (used in) financing activities 2.7 (332.2 ) 69.4 85.7 (174.4 ) INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS (3.4 ) (256.5 ) 224.4 — (35.5 ) CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD 3.7 532.0 719.8 — 1,255.5 CASH AND CASH EQUIVALENTS, END OF PERIOD $ 0.3 $ 275.5 $ 944.2 $ — $ 1,220.0

Subsequent Event (Notes)

Subsequent Event (Notes)	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events Proposed Merger of Rowan Companies plc and Ensco plc On October 7, 2018, the Company entered into a Transaction Agreement with Ensco plc to effect a "merger-of-equals" transaction (see Note 1 ). Sale of Rigs to ARO Effective October 1, 2018, the Company sold two jack-ups to ARO (see Note 1 ).

Nature of Operations and Basi_2

Nature of Operations and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The financial statements included in this Quarterly Report have been prepared in accordance with US GAAP and the applicable rules and regulations of the SEC. Certain information and notes have been condensed or omitted as permitted by those rules and regulations. The financial information included in this report is unaudited, but management believes the accompanying financial statements contain all adjustments, which are of a normal recurring nature unless otherwise noted, necessary for a fair statement of the financial position, results of operations and cash flows for the interim periods presented. The preparation of the condensed consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. The Company’s results of operations and cash flows for the interim periods are not necessarily indicative of results to be expected for the full year. These financial statements should be read in conjunction with the audited consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (as recast in part on Forms 8-K filed with the SEC on May 9, 2018 and August 24, 2018).
Revenue Recognition	Revenue Recognition In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (ASC 606) , which sets forth a global standard for revenue recognition and replaces most existing industry-specific guidance. ASC 606 requires an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company adopted ASC 606, effective January 1, 2018, utilizing the modified retrospective approach and applied ASC 606 to all outstanding revenue contracts. In adopting ASC 606, the Company's revenue recognition differs from its historical revenue recognition pattern primarily as it relates to demobilization revenue. Such revenue, which was recognized upon completion of a contract under legacy accounting, is now estimated at contract inception and recognized over the term of the contract under the new guidance for customer contracts that have unconstrained demobilization provisions. Upon adoption of this standard as of January 1, 2018, the Company recognized a $5.5 million increase to retained earnings related to unconstrained demobilization provisions. Subsequently, during the first quarter of 2018, the Company received a $5.5 million cash payment for such demobilization related to one of the Company's contracts. The adoption of this standard did not have a material impact on our statements of operations or statements of cash flows. Typical contractual arrangements The Company contracts its drilling rigs, related equipment and work crews primarily on a “day rate” basis. Under day rate contracts, the Company generally receives a fixed amount per day for each day it is performing drilling or related services. In addition, customers may pay all or a portion of the cost of moving equipment and personnel to and from the well site. Contracts generally range in duration from one month to multiple years or alternatively may be based on a set number of wells. Both duration types can include additional option periods at the discretion of the customer which can be at a set price or may be determined upon exercise of the option. The contractual day rate generally varies based on the status of the drilling operations and generally includes an operating rate, move rate, repair rate, force majeure, standby rate, or other fixed type of day rate specified in the contract. Other fees may be stipulated in the contract related to mobilization and demobilization of the rig, upfront preparation and/or upgrades, penalties, performance bonuses and reimbursements for third party charges or requested modifications. Termination clauses are also specified and generally allow the customer to cancel for lack of performance by the contractor with no related fee or for convenience for an early termination fee, typically calculated as a standby rate multiplied by the days remaining in the firm term in the contract often reduced by a specified percentage. Performance obligations and transaction price Customers generally contract for a comprehensive agreement to provide integrated services to operate a rig and drill a well. Drillers are seen by the operator as the overseer of all services and are compensating the driller to provide that entire suite of services. In identifying performance obligations, ASC 606 series guidance states that a contract may contain a single performance obligation composed of a series of distinct goods or services if 1) each distinct good or service is substantially the same and would meet the criteria to be a performance obligation satisfied over time and 2) each distinct good or service is measured using the same method as it relates to the satisfaction of the overall performance obligation. The Company determined that the delivery of day rate drilling services is within the scope of the series guidance as both criteria noted above are met. Specifically, 1) each distinct increment of service (i.e. hour available to drill) that the driller promises to transfer represents a performance obligation that would meet the criteria for recognizing revenue over time, and 2) the driller would use the same method for measuring progress toward satisfaction of the performance obligation for each distinct increment of service in the series. Consideration for activities that are not distinct within the scope of our contracts, such as mobilization, demobilization and upgrade/modification, and do not align with a distinct time increment within the contract term are allocated across the single performance obligation and are recognized over the expected recognition period in proportion to the passage of each hour available to drill. Consideration for activities which align with a distinct time increment within the contract term is recognized in the period when the services are performed. The transaction price for a drilling contract is based on the amount of consideration the Company expects to be entitled for providing drilling services over the specified term and includes both fixed amounts and unconstrained variable amounts. Typically, at contract commencement, the only fixed/known consideration components of a drilling contract are negotiated lump-sum amounts to be received for reimbursement of costs incurred for mobilization, demobilization (where it is contractually guaranteed) and/or rig modifications or upgrades. The Company estimates variable consideration using the expected value method and includes the amount in transaction price to the extent it is not constrained. Variable consideration is generally constrained if it is probable that a significant reversal in the amount of cumulative revenue recognized will occur when the uncertainty associated with the variable consideration is subsequently resolved. Recognition of revenue Drilling services are consumed as the services are performed and generally enhance a well site which the customer/operator controls. Work performed on a well site does not create an asset with an alternative use to the contractor since the well/asset being worked on is owned by the customer. Therefore, the Company’s measure of progress for a drilling contract is hours available to drill over the contracted duration. This unit of measure is representative of an output method as described in ASC 606. The following chart details the types of fees found in a typical drilling contract and the related recognition method under ASC 606: Fee type Revenue Recognition Day rate Recognition is based on the day rates earned/invoiced as it relates to the level of service provided for each fractional-hour throughout the contract. Mobilization and upgrade/modification Revenue (both lump-sum and day rate amounts) is estimated at contract inception and included in the transaction price to be recognized over the expected recognition period. Demobilization Unconstrained demobilization revenue (both lump-sum and day rate amounts) is estimated at contract inception, included in the transaction price, and recognized over the expected recognition period in proportion to the passage of each hour available to drill. Bonuses and penalty Unconstrained bonus and/or penalty revenue is estimated at contract inception and included in the transaction price. Amounts are recognized in the period corresponding to the distinct hourly increment(s) of service provided (i.e. the specific period which the bonus or penalty relates to). Reimbursement Recognized (gross of costs incurred), at the point the product or service is consumed, and in the amount billed to the customer. Future performance obligation and financing arrangements Due to the recognition of day rate, as described above, the Company's primary future promised service relates to unconstrained demobilization. Under ASC 606 the Company recognizes unconstrained demobilization revenue over the life of the contract whereas in a typical drilling contract the demobilization, and the resulting cash payment for demobilization, does not occur until the end of the contract. At September 30, 2018 , the Company had a contract asset of $5.3 million for unconstrained demobilization revenue (see Note 2 ) related to the Company recognizing $5.3 million in unconstrained demobilization revenue into income during the three and nine months ended September 30, 2018 . We expect to recognize the remaining $3.2 million of our total estimated $8.5 million of unconstrained demobilization into revenue during the remainder of 2018 and 2019 in the amount of $1.5 million and $1.7 million , respectively. We have applied the optional exemption afforded in ASU No. 2014-09 and have not disclosed the variable consideration related to the estimated future day rate revenues. Upon adoption of this standard as of January 1, 2018, the Company recognized a $5.5 million increase to retained earnings related to unconstrained demobilization provisions. Subsequently, during the first quarter of 2018, the Company received a $5.5 million cash payment for such demobilization related to one of the Company's contracts. Under ASC 606, a significant financing component may exist, regardless of whether the promise is explicitly stated or implied by the payment terms stipulated in a contract, where there is a separation between the timing of services provided and the timing of payment in contracts with terms exceeding one year. Generally, a typical drilling contract stipulates for billings on a monthly basis and payment terms vary by contract and customer but are customarily paid within 90 days. It is rare for a drilling contract to explicitly address a financing component and payments of up-front fees correspond to cash outlays which Rowan must undertake in order to complete a given drilling contract.
New Accounting Pronouncements	Recently Adopted Accounting Pronouncements - In addition to Revenue from Contracts with Customers (ASC 606) (see "Revenue Recognition" above), the Company has recently adopted the following accounting pronouncements: Statement of Cash Flows - In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (ASC 230): Classification of Certain Cash Receipts and Cash Payments, which provides guidance on eight cash flow classification issues with the objective of reducing differences in practice. As of January 1, 2018, the Company adopted this guidance on a retrospective basis with no material impact on its condensed consolidated financial statements. Statement of Cash Flows Restricted Cash - In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (ASC 230): Restricted Cash , which requires restricted cash to be presented with cash and cash equivalents in the statement of cash flows. The changes in restricted cash and restricted cash equivalents during the period should be included in the beginning and ending cash and cash equivalents balance reconciliation on the statement of cash flows. When cash, cash equivalents, restricted cash or restricted cash equivalents are presented in more than one line item within the statement of financial position, an entity shall calculate a total cash amount in a narrative or tabular format that agrees with the amount shown on the statement of cash flows. Details on the nature and amounts of restricted cash should also be disclosed. As of January 1, 2018, the Company adopted this guidance on a retrospective basis with no impact on its condensed consolidated financial statements. Other Income - In February 2017, the FASB issued ASU No. 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (“ASU 2017-05”), which clarifies the scope of the original guidance within Subtopic 610-20 that was issued in connection with ASU 2014-09, which provides guidance for recognizing gains and losses from the transfer of nonfinancial assets in contracts with non-customers. ASU 2017-05 also adds guidance for partial sales of nonfinancial assets. As of January 1, 2018, the Company adopted this guidance on a modified retrospective basis concurrently with ASC 606. This adoption had no impact on the Company's condensed consolidated financial statements. Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost - In March 2017, the FASB issued ASU No. 2017-07, Compensation - Retirement Benefits (ASC 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, which requires entities to present the service cost component of the net periodic benefit cost in the same income statement line item as other employee compensation costs. The other components of net benefit cost, including interest cost, expected return on plan assets, amortization of prior service cost/credit and actuarial gain/loss, and settlement and curtailment effects, are to be presented outside of any subtotal of operating income. Entities will have to disclose the line(s) used to present the other components of net periodic benefit cost, if the components are not presented separately in the income statement . The ASU also allows only the service cost component to be eligible for capitalization. As of January 1, 2018, the Company adopted this guidance on a retrospective basis with no material impact on its condensed consolidated financial statements. Accumulated Other Comprehensive Income – In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (ASC 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , which allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017. As permitted under this ASU, the Company elected early adoption of this ASU as of January 1, 2018 and recorded a $45.6 million increase to Retained earnings as a reclassification from Accumulated other comprehensive income. The stranded tax effects are for the U.S. income tax rate reduction recognized in the Consolidated Statements of Operations for the year ended December 31, 2017 for the deferred tax asset associated with employee benefit plans. New Accounting Pronouncements - to be adopted Lease Accounting – In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842) : Amendments to the FASB ASC, which requires an entity to recognize lease assets and lease liabilities on the balance sheet and to disclose key qualitative and quantitative information about the entity's leasing arrangements. Based on the original guidance, lessees and lessors would have been required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach, including a number of optional practical expedients that entities may elect to apply. In July 2018, the FASB issued ASU No. 2018-11, Leases (ASC 842): Targeted Improvements , which provides entities with an option to apply the guidance prospectively, instead of retrospectively, and allows for other classification provisions, as described below. ASC 842 is effective for annual and interim periods beginning after December 15, 2018. The Company will elect to recognize its lease asset and lease liabilities on a prospective basis, beginning on January 1, 2019. Prior to the issuance of ASU No. 2018-11, the Company preliminarily determined that its drilling contracts contained a lease component, and the adoption would require the Company to separately recognize revenue associated with the lease and services components. In July 2018, the FASB issued ASU No. 2018-11, which provides a practical expedient that allows entities to combine lease and non-lease components where the revenue recognition pattern is the same and where the lease component, when accounted for separately, would be considered an operating lease. With respect to the applicability of this practical expedient to the drilling industry, the Company continues to evaluate ASU No. 2018-11 and is working with its peers in the International Association of Drilling Contractors Accounting Sub-committee to discuss the applicability of this practical expedient to its drilling contracts. The adoption of ASC 842 will have an impact on how the Company's consolidated balance sheets, statements of operations, and disclosures contained in its notes to consolidated financial statements will be presented; however, because the Company continues to evaluate the impact of ASU No. 2018-11, it is unable to quantify the overall impact at this time. As a lessee, estimated future minimum lease commitments are approximately $30 million with an estimated present value of approximately $25 million based on the Company's currently identified lease portfolio. The Company will continue to refine its estimate, which is subject to change at the adoption date of ASC 842. Financial Instruments – In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (ASC 326): Measurement of Credit Losses on Financial Instruments, which amends the FASB's guidance on the impairment of financial instruments. The ASU adds to US GAAP an impairment model that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes as an allowance its estimate of expected credit losses. The Company will be required to adopt the amended guidance in annual and interim reports beginning January 1, 2020, with early adoption permitted for fiscal years beginning after December 15, 2018. The Company is in the process of evaluating the impact this amendment will have on its consolidated financial statements . Fair Value Measurement - In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (ASC 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement, which removes, modifies and adds certain disclosure requirements on fair value measurements including (i) removal of the requirements to disclose the amounts and reasons for as well as the policy for timing of transfers between Level 1 and Level 2 as well as descriptions of valuation processes used for for Level 3 fair value measurements; (ii) certain modifications including clarification that the measurement uncertainty disclosure is to communicate information about the uncertainty in measurement as of the reporting date and; (iii) add disclosures related to changes in unrealized gains and losses for the period included in other comprehensive income (loss) for recurring Level 3 fair value measurements held at the end of the reporting period as well as disclosures for the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The Company will be required to adopt the amended guidance in annual and interim reports beginning January 1, 2020, with early adoption permitted. Adoption is required to be applied prospectively with respect to the amendments on changes in unrealized gains and losses, range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements and narrative description of measurement uncertainty. All other amendments are to be applied retrospectively to all periods presented. The Company is in the process of evaluating the impact this amendment will have on its consolidated financial statements . Defined Benefit Plans - In August 2018, the FASB issued ASU No. 2018-14, Compensation – Retirement Benefits – Defined Benefit Plans – General (Subtopic 715-20): Disclosure Framework – Changes to the Disclosure Requirements for Defined Benefit Plans, which modifies the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The Company will be required to adopt the amended guidance in annual and interim reports beginning January 1, 2021, with early adoption permitted. Adoption is required to be applied on a retrospective basis to all periods presented. The Company is in the process of evaluating the impact this amendment will have on its consolidated financial statements . Internal Use Software - In August 2018, the FASB issued ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (a consensus of the FASB Emerging Issues Task Force), which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The Company will be required to adopt the amended guidance in annual and interim reports beginning January 1, 2020, with early adoption permitted. Adoption may be applied retrospectively or prospectively to implementation costs incurred after the date of adoption. The Company is in the process of evaluating the impact this amendment will have on its consolidated financial statements .

Contract Assets and Contract _2

Contract Assets and Contract Liabilities (Tables)	9 Months Ended
	Sep. 30, 2018
Contract with Customer, Asset and Liability [Abstract]
Schedule of Contract Assets and Contract Liabilities	Presented in the table below are the changes in deferred contract costs during the nine months ended September 30, 2018 (in millions): September 30, 2018 Deferred Contract Costs Asset Beginning balance $ 2.8 Plus: contractual additions 4.8 Less: amortization 5.8 Ending balance $ 1.8 Presented in the table below are the changes in deferred revenue during the nine months ended September 30, 2018 (in millions): September 30, 2018 Deferred Revenue - Deferred mobilization and upgrade/modification revenue Beginning balance $ 1.6 Plus: contractual additions (1) 45.5 Less: amortization 9.1 Ending balance $ 38.0 (1) Includes $28.6 million of deferred revenue related to capital expenditures for the Bess Brants , Earnest Dees , EXL I and EXL IV (all leased to ARO) to be received as reimbursement from ARO. A receivable of $28.6 million is included in Receivables - trade and other on the Condensed Consolidated Balance Sheet at September 30, 2018. Presented in the table below are the changes in contract assets (See Note 1 ) during the nine months ended September 30, 2018 (in millions): September 30, 2018 Contract Assets - Demobilization Beginning balance $ — Plus: contractual additions 5.3 Ending balance $ 5.3 The following table sets forth deferred contract costs, demobilization contract assets and deferred revenue on the Condensed Consolidated Balance Sheets (in millions): Balance Sheet Classification September 30, 2018 December 31, 2017 Deferred Contract Costs and Demobilization Contract Assets Current Prepaid expenses and other current assets $ 6.7 $ 2.8 Noncurrent Other assets 0.4 — $ 7.1 $ 2.8 Deferred Revenue - Contract liabilities Current Deferred revenue $ 17.8 $ 1.1 Noncurrent Other liabilities 20.2 0.5 $ 38.0 $ 1.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]	Estimated future amortization at September 30, 2018 of our deferred revenue and deferred contract costs to be recognized over the expected recognition period is set forth in the following table (in millions): Remaining 2018 2019 2020 2021 Total Amortization of deferred revenue $ 6.2 $ 13.9 $ 9.6 $ 8.3 $ 38.0 Amortization of deferred contract costs 0.9 0.6 0.2 0.1 1.8

Equity Method Investments and_2

Equity Method Investments and Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Related Party Transactions [Table Text Block]	Revenue and other amounts recognized by Rowan related to these agreements and transactions is as follows (in millions): Three months ended September 30, 2018 Nine months ended September 30, 2018 Secondment Revenue - Jack-ups $ 14.4 $ 36.2 Lease Revenue - Jack-ups 8.0 9.1 Transition Services Revenue - Unallocated 9.0 26.9 Sales of supplies - Jack-ups 2.0 3.9 Total Revenue received from ARO $ 33.4 $ 76.1 Proceeds from equipment sales to ARO (a) $ 5.9 $ 7.6 (a) A gain of $0.9 million and $0.7 million for the three and nine months ended September 30, 2018, respectively, was recognized in Loss on disposals of property and equipment on the Condensed Consolidated Statements of Operations. $6.8 million is included in Receivables - trade and other as of September 30, 2018 for the $7.6 million purchase price proceeds.
Equity Method Investments [Table Text Block]	The following summarizes the total assets and liabilities as reflected in the Company's Condensed Consolidated Balance Sheets as well as the Company's maximum exposure to loss related to ARO (in millions). Generally, the Company's maximum exposure to loss is limited to its 1) equity investment in the joint venture, 2) outstanding note receivable and 3) any amounts receivable by the Company for services it provides to the joint venture, reduced by payables for services which the Company owes to ARO. September 30, 2018 December 31, 2017 Total assets $ 370.3 $ 319.5 Total liabilities 11.3 10.8 Maximum exposure to loss $ 359.0 $ 308.7 Summarized financial information for ARO, as derived from ARO's financial statements, is as follows (in millions): Three months ended September 30, 2018 Nine months ended September 30, 2018 Revenue $ 89.2 $ 218.3 Direct operating costs (excluding items below) 51.2 120.5 Depreciation and amortization 17.0 50.4 Selling, general and administrative 6.8 20.0 Gain on disposals of property and equipment (1.0 ) — Income from operations 15.2 27.4 Interest expense (5.7 ) (16.9 ) Provision for income taxes 3.2 3.6 Net income $ 6.3 $ 6.9 Rowan's equity in earnings from ARO $ 3.1 $ 3.4 September 30, 2018 December 31, 2017 Current assets $ 205.8 $ 108.6 Non-current assets 468.8 459.7 Total assets $ 674.6 $ 568.3 Current liabilities $ 107.4 $ 29.2 Non-current liabilities 566.3 545.1 Total liabilities $ 673.7 $ 574.3

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Antidilutive Securities Excluded From Earnings per Share	Anti-dilutive shares, which could potentially dilute earnings per share in the future, are set forth below (in millions): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Share options and appreciation rights 1.5 1.7 1.5 1.7 P-Units and RSUs 4.0 4.0 4.2 3.9 Total potentially dilutive shares 5.5 5.7 5.7 5.6

Pension and Other Postretirem_2

Pension and Other Postretirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2018
Retirement Benefits [Abstract]
Summary of Net Periodic Pension and Other Postemployment Benefit Costs	The components of net periodic pension cost were as follows (in millions): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Service cost (1) $ 0.4 $ 1.2 $ 5.7 $ 9.2 Interest cost (2) 7.3 6.4 20.7 19.1 Expected return on plan assets (2) (9.2 ) (9.3 ) (27.3 ) (28.2 ) Amortization of net loss (2) 2.4 5.9 16.1 17.4 Amortization of prior service credit (2) (0.1 ) (1.3 ) (1.7 ) (3.8 ) Curtailment gain (2) — — (11.4 ) — Net periodic pension cost $ 0.8 $ 2.9 $ 2.1 $ 13.7 (1) Included in Direct operating costs and Selling, general and administrative on the Condensed Consolidated Statements of Operations (2) Included in Other - net on the Condensed Consolidated Statements of Operations The components of net periodic cost of other postretirement benefits were as follows (in millions): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Service cost (1) $ — $ — $ — $ 0.1 Interest cost (2) 0.1 0.2 0.4 0.7 Amortization of net loss (2) 0.2 0.2 0.6 0.5 Amortization of prior service credit (2) (3.3 ) (3.3 ) (9.9 ) (9.9 ) Total other postretirement benefit cost $ (3.0 ) $ (2.9 ) $ (8.9 ) $ (8.6 ) (1) Included in Direct operating costs and Selling, general and administrative on the Condensed Consolidated Statements of Operations (2) Included in Other - net on the Condensed Consolidated Statements of Operations
Schedule of Changes in Projected Benefit Obligations [Table Text Block]	The impacts of these changes to the plan as of May 11, 2018, are presented in the table below (in millions): Liability increase (decrease) Accumulated other comprehensive income (loss) Deferred tax asset decrease (increase) Income included in Other- net Income tax expense (increase) decrease Plan change to projected benefit obligation $ (1.6 ) $ 1.3 $ 0.3 $ — $ — Remeasurement gain (29.9 ) 23.6 6.3 — — Curtailment — (9.0 ) (1.0 ) 11.4 (1.4 ) Total $ (31.5 ) $ 15.9 $ 5.6 $ 11.4 $ (1.4 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis [Table Text Block]	Assets measured at fair value on a recurring basis are presented below (in millions): Estimated fair value measurements Fair value Quoted prices in active markets (Level 1) Significant other observable inputs (Level 2) Significant other unobservable inputs (Level 3) September 30, 2018: Assets - cash equivalents $ 1,015.7 $ 1,015.7 $ — $ — Other assets (Egyptian Pounds) 1.4 1.4 — — Other assets (Angolan Kwanza) 2.5 2.5 — — December 31, 2017: Assets - cash equivalents $ 1,332.1 $ 1,332.1 $ — $ — Other assets (Egyptian Pounds) 2.2 2.2 — — Other assets (Angolan Kwanza) 4.3 4.3 — —
Fair Value, Concentration of Risk [Table Text Block]	Revenue and receivables from transactions with external customers that amount to 10% or more of revenue during the nine months ended September 30 are set forth below: Percentage of revenue from major customers: Nine months ended September 30, Customer Segment 2018 2017 Saudi Aramco Jack-ups 34 % 29 % Anadarko Deepwater 18 % 16 % ARO Drilling Jack-ups and Unallocated and other 12 % — % Shell Jack-ups 6 % — % Cobalt International Deepwater — % 14 % Percentage of receivables from major customers: Customer Segment September 30, 2018 December 31, 2017 Saudi Aramco Jack-ups 43 % 34 % Anadarko Deepwater — % 19 % ARO Drilling (1) Jack-ups and Unallocated and other 23 % 9 % Shell Jack-ups 12 % — % Cobalt International Deepwater — % — % (1) Includes receivables related to the services provided to ARO (see Note 3 ).

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Schedule of Amounts Reclassified out of Each Component of Accumulated Other Comprehensive Loss	The following table sets forth the significant amounts reclassified out of each component of accumulated other comprehensive loss and their effect on net income (loss) for the period (in millions): Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Amounts recognized as a component of net periodic pension and other postretirement benefit cost: Amortization of net loss $ (2.6 ) $ (6.1 ) $ (16.7 ) $ (17.9 ) Amortization of prior service credit 3.4 4.6 11.6 13.7 Total before income taxes 0.8 (1.5 ) (5.1 ) (4.2 ) Income tax (expense) benefit (0.1 ) 0.5 1.1 1.5 Total reclassifications for the period, net of income taxes $ 0.7 $ (1.0 ) $ (4.0 ) $ (2.7 )

Other Financial Statement Dis_2

Other Financial Statement Disclosures (Tables)	9 Months Ended
	Sep. 30, 2018
Other Financial Statement Disclosures [Abstract]
Components of Receivables - Trade and Other	The following table sets forth the components of Receivables - trade and other (in millions): September 30, 2018 December 31, 2017 Trade $ 260.1 $ 195.8 Income tax 15.1 8.0 Other 6.3 9.0 Total Receivables - trade and other $ 281.5 $ 212.8
Schedule of Accrued Liabilities	The following table sets forth the components of Accrued liabilities (in millions): September 30, 2018 December 31, 2017 Pension and other postretirement benefits $ 10.3 $ 27.0 Compensation and related employee costs 41.2 69.0 Interest 39.6 32.0 Income taxes 13.5 15.4 Other 17.6 15.7 Total Accrued liabilities $ 122.2 $ 159.1
Schedule of Long-term Debt	Long-term debt consisted of the following (in millions): September 30, 2018 December 31, 2017 7.875% Senior Notes, due August 2019 ($201.4 million principal amount; 8.0% effective rate) $ 201.1 $ 200.9 4.875% Senior Notes, due June 2022 ($620.8 million principal amount; 4.7% effective rate) 624.0 624.6 4.75% Senior Notes, due January 2024 ($398.1 million principal amount; 4.8% effective rate) 396.2 395.9 7.375% Senior Notes, due June 2025 ($500 million principal amount; 7.4% effective rate) 497.8 497.5 5.4% Senior Notes, due December 2042 ($400 million principal amount; 5.4% effective rate) 395.2 395.1 5.85% Senior Notes, due January 2044 ($400 million principal amount; 5.9% effective rate) 396.4 396.3 Total carrying value $ 2,510.7 $ 2,510.3 Current portion (1) 201.1 — Carrying value, less current portion $ 2,309.6 $ 2,510.3 (1) Current portion of long-term debt at September 30, 2018 included the 7.875% Senior Notes due in August 2019.
Line of Credit Facility Covenant	the Company was in compliance with each of the financial covenants under the New Credit Agreement as follows: Min/Max Value as of Financial covenant Requirement September 30, 2018 Total tangible capitalization 55 % 33 % Liquidity (in millions) $ 300.0 $ 2,292.7 Marketed Rig Value Ratio 3.00 4.14 Guaranteed Rig Value Ratio 80 % 84 %

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Schedule of Segment Information	Segment results are presented below (in millions): Three months ended September 30, Deepwater Jack-ups ARO Unallocated and other Reportable segments total Eliminations and adjustments Consolidated 2018 Revenue $ 13.9 $ 170.0 $ 89.2 $ 9.0 $ 282.1 $ (89.2 ) $ 192.9 Operating expenses: Direct operating costs (excluding items below) 48.4 133.9 51.2 — 233.5 (51.2 ) 182.3 Depreciation and amortization 27.3 71.1 17.0 0.6 116.0 (17.0 ) 99.0 Selling, general and administrative — — 6.8 26.6 33.4 (6.8 ) 26.6 Other operating items - (income) expense — 1.5 (1.0 ) — 0.5 1.0 1.5 Equity in earnings of unconsolidated subsidiary — — — — — 3.1 3.1 Income (loss) from operations $ (61.8 ) $ (36.5 ) $ 15.2 $ (18.2 ) $ (101.3 ) $ (12.1 ) $ (113.4 ) 2017 Revenue $ 88.4 $ 203.2 $ — $ — $ 291.6 $ — $ 291.6 Operating expenses: Direct operating costs (excluding items below) 33.2 135.5 — — 168.7 — 168.7 Depreciation and amortization 27.4 75.3 — 0.7 103.4 — 103.4 Selling, general and administrative — — — 24.9 24.9 — 24.9 Other operating items - expense — 2.7 — 0.1 2.8 — 2.8 Income (loss) from operations $ 27.8 $ (10.3 ) $ — $ (25.7 ) $ (8.2 ) $ — $ (8.2 ) Nine months ended September 30, Deepwater Jack-ups ARO Unallocated and other Reportable segments total Eliminations and adjustments Consolidated 2018 Revenue $ 131.8 $ 486.7 $ 218.3 $ 26.9 $ 863.7 $ (218.3 ) $ 645.4 Operating expenses: Direct operating costs (excluding items below) 118.2 397.8 120.5 — 636.5 (120.5 ) 516.0 Depreciation and amortization 81.2 211.3 50.4 1.8 344.7 (50.4 ) 294.3 Selling, general and administrative — — 20.0 77.4 97.4 (20.0 ) 77.4 Other operating items - expense — 5.0 — — 5.0 — 5.0 Equity in earnings of unconsolidated subsidiary — — — — — 3.4 3.4 Income (loss) from operations $ (67.6 ) $ (127.4 ) $ 27.4 $ (52.3 ) $ (219.9 ) $ (24.0 ) $ (243.9 ) 2017 Revenue $ 371.8 $ 614.3 $ — $ — $ 986.1 $ — $ 986.1 Operating expenses: Direct operating costs (excluding items below) 117.1 391.7 — — 508.8 — 508.8 Depreciation and amortization 84.1 217.8 — 2.1 304.0 — 304.0 Selling, general and administrative — — — 71.3 71.3 — 71.3 Other operating items - expense — 9.3 — — 9.3 — 9.3 Income (loss) from operations $ 170.6 $ (4.5 ) $ — $ (73.4 ) $ 92.7 $ — $ 92.7
Revenue from External Customers by Products and Services [Table Text Block]	The classifications of revenue among geographic areas in the tables which follow (in millions) were determined based on segment and physical location of assets. Because the Company evaluates performance primarily based on income from operations and the Company’s offshore drilling rigs are mobile, classifications by area are dependent on the rigs’ location at the time revenue is earned and may vary from one period to the next. Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Deepwater Revenue: United States $ 13.9 $ 88.4 $ 131.8 $ 369.4 Other — — — 2.4 Total $ 13.9 $ 88.4 $ 131.8 $ 371.8 Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Jack-ups Revenue: Saudi Arabia $ 88.8 $ 102.7 $ 270.8 $ 290.2 Norway 2.3 45.8 65.7 140.9 Trinidad 39.8 30.3 83.1 106.3 United Kingdom 28.8 12.7 50.7 41.9 United States 10.3 11.7 16.4 34.9 Other — — — 0.1 Total $ 170.0 $ 203.2 $ 486.7 $ 614.3 Three months ended September 30, Nine months ended September 30, 2018 2017 2018 2017 Unallocated and Other Revenue: Saudi Arabia $ 9.0 $ — $ 26.9 $ — Total $ 9.0 $ — $ 26.9 $ —

Guarantees of Registered Secu_2

Guarantees of Registered Securities (Tables)	9 Months Ended
	Sep. 30, 2018
Condensed Financial Information Disclosure [Abstract]
Condensed Consolidating Income Statements	Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Operations Three months ended September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated REVENUE $ — $ 1.7 $ 192.9 $ (1.7 ) $ 192.9 COSTS AND EXPENSES: Direct operating costs (excluding items below) — — 182.3 — 182.3 Depreciation and amortization — — 99.0 — 99.0 Selling, general and administrative 7.6 — 20.7 (1.7 ) 26.6 (Gain) loss on disposals of property and equipment — (0.7 ) 2.2 — 1.5 Total costs and expenses 7.6 (0.7 ) 304.2 (1.7 ) 309.4 Equity in earnings of unconsolidated subsidiary — — 3.1 — 3.1 INCOME (LOSS) FROM OPERATIONS (7.6 ) 2.4 (108.2 ) — (113.4 ) OTHER INCOME (EXPENSE): Interest expense — (37.3 ) (2.4 ) 0.5 (39.2 ) Interest income — 0.5 8.0 (0.5 ) 8.0 Other - net 5.1 (4.5 ) 3.4 — 4.0 Total other income (expense), net 5.1 (41.3 ) 9.0 — (27.2 ) LOSS BEFORE INCOME TAXES (2.5 ) (38.9 ) (99.2 ) — (140.6 ) Provision (benefit) for income taxes — 3.8 (0.3 ) — 3.5 Equity in earnings (losses) of subsidiaries, net of tax (141.6 ) 39.3 — 102.3 — NET LOSS $ (144.1 ) $ (3.4 ) $ (98.9 ) $ 102.3 $ (144.1 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Operations Three months ended September 30, 2017 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated REVENUE $ — $ 0.6 $ 291.8 $ (0.8 ) $ 291.6 COSTS AND EXPENSES: Direct operating costs (excluding items below) — 0.4 171.5 (3.2 ) 168.7 Depreciation and amortization — 4.4 99.0 — 103.4 Selling, general and administrative 7.0 0.1 15.4 2.4 24.9 (Gain) loss on disposals of property and equipment — (0.1 ) 2.9 — 2.8 Total costs and expenses 7.0 4.8 288.8 (0.8 ) 299.8 INCOME (LOSS) FROM OPERATIONS (7.0 ) (4.2 ) 3.0 — (8.2 ) OTHER INCOME (EXPENSE): Interest expense — (38.5 ) (0.1 ) 0.1 (38.5 ) Interest income — 0.9 2.9 (0.1 ) 3.7 Loss on extinguishment of debt — (0.5 ) — — (0.5 ) Other - net 5.1 (5.0 ) 0.7 — 0.8 Total other income (expense) - net 5.1 (43.1 ) 3.5 — (34.5 ) INCOME (LOSS) BEFORE INCOME TAXES (1.9 ) (47.3 ) 6.5 — (42.7 ) Benefit for income taxes — (0.6 ) (22.2 ) 1.0 (21.8 ) Equity in earnings (losses) of subsidiaries, net of tax (19.0 ) 47.6 — (28.6 ) — NET INCOME (LOSS) $ (20.9 ) $ 0.9 $ 28.7 $ (29.6 ) $ (20.9 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Operations Nine months ended September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated REVENUE $ — $ 3.7 $ 645.4 $ (3.7 ) $ 645.4 COSTS AND EXPENSES: Direct operating costs (excluding items below) — — 516.0 — 516.0 Depreciation and amortization — — 294.3 — 294.3 Selling, general and administrative 20.3 0.5 60.3 (3.7 ) 77.4 (Gain) loss on disposals of property and equipment — (0.1 ) 5.1 — 5.0 Total costs and expenses 20.3 0.4 875.7 (3.7 ) 892.7 Equity in earnings of unconsolidated subsidiary — — 3.4 — 3.4 INCOME (LOSS) FROM OPERATIONS (20.3 ) 3.3 (226.9 ) — (243.9 ) OTHER INCOME (EXPENSE): Interest expense — (113.8 ) (4.2 ) 1.4 (116.6 ) Interest income — 2.5 21.5 (1.4 ) 22.6 Other - net 15.1 (12.3 ) 7.8 — 10.6 Total other income (expense), net 15.1 (123.6 ) 25.1 — (83.4 ) LOSS BEFORE INCOME TAXES (5.2 ) (120.3 ) (201.8 ) — (327.3 ) Provision (benefit) for income taxes — (3.7 ) 9.5 — 5.8 Equity in earnings (losses) of subsidiaries, net of tax (327.9 ) 138.5 — 189.4 — NET INCOME (LOSS) $ (333.1 ) $ 21.9 $ (211.3 ) $ 189.4 $ (333.1 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Operations Nine months ended September 30, 2017 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated REVENUES $ — $ 38.2 $ 986.6 $ (38.7 ) $ 986.1 COSTS AND EXPENSES: Direct operating costs (excluding items below) — 1.2 542.2 (34.6 ) 508.8 Depreciation and amortization — 14.4 289.4 0.2 304.0 Selling, general and administrative 18.8 2.0 54.8 (4.3 ) 71.3 Loss on disposals of property and equipment — 1.6 7.7 — 9.3 Total costs and expenses 18.8 19.2 894.1 (38.7 ) 893.4 INCOME (LOSS) FROM OPERATIONS (18.8 ) 19.0 92.5 — 92.7 OTHER INCOME (EXPENSE): Interest expense — (117.1 ) (0.3 ) 0.4 (117.0 ) Interest income — 2.6 6.7 (0.4 ) 8.9 Gain on extinguishment of debt — 1.7 — — 1.7 Other - net 15.4 (14.6 ) 2.9 — 3.7 Total other income (expense) - net 15.4 (127.4 ) 9.3 — (102.7 ) INCOME (LOSS) BEFORE INCOME TAXES (3.4 ) (108.4 ) 101.8 — (10.0 ) Provision (benefit) for income taxes — (10.8 ) 40.1 29.3 Equity in earnings (losses) of subsidiaries, net of tax (35.9 ) 66.7 — (30.8 ) — NET INCOME (LOSS) $ (39.3 ) $ (30.9 ) $ 61.7 $ (30.8 ) $ (39.3 )
Statements of Comprehensive Income (Loss)	Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Comprehensive Loss Three months ended September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET LOSS $ (144.1 ) $ (3.4 ) $ (98.9 ) $ 102.3 $ (144.1 ) OTHER COMPREHENSIVE LOSS: Net reclassification adjustment for amounts recognized in net loss as a component of net periodic benefit cost, net of income taxes (0.7 ) (0.7 ) — 0.7 (0.7 ) COMPREHENSIVE LOSS $ (144.8 ) $ (4.1 ) $ (98.9 ) $ 103.0 $ (144.8 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Comprehensive Income (Loss) Three months ended September 30, 2017 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET INCOME (LOSS) $ (20.9 ) $ 0.9 $ 28.7 $ (29.6 ) $ (20.9 ) OTHER COMPREHENSIVE INCOME: Net reclassification adjustment for amounts recognized in net income (loss) as a component of net periodic benefit cost, net of income taxes 1.0 1.0 — (1.0 ) 1.0 COMPREHENSIVE INCOME (LOSS) $ (19.9 ) $ 1.9 $ 28.7 $ (30.6 ) $ (19.9 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Comprehensive Income (Loss) Nine months ended September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET INCOME (LOSS) $ (333.1 ) $ 21.9 $ (211.3 ) $ 189.4 $ (333.1 ) OTHER COMPREHENSIVE INCOME: Net changes in pension and other postretirement plan assets and benefit obligations recognized in other comprehensive income, net of income taxes 15.9 15.9 — (15.9 ) 15.9 Net reclassification adjustment for amounts recognized in net income (loss) as a component of net periodic benefit cost, net of income taxes 4.0 4.0 — (4.0 ) 4.0 19.9 19.9 — (19.9 ) 19.9 COMPREHENSIVE INCOME (LOSS) $ (313.2 ) $ 41.8 $ (211.3 ) $ 169.5 $ (313.2 ) Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Comprehensive Income (Loss) Nine months ended September 30, 2017 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET INCOME (LOSS) $ (39.3 ) $ (30.9 ) $ 61.7 $ (30.8 ) $ (39.3 ) OTHER COMPREHENSIVE INCOME: Net reclassification adjustment for amounts recognized in net income (loss) as a component of net periodic benefit cost, net of income taxes 2.7 2.7 — (2.7 ) 2.7 COMPREHENSIVE INCOME (LOSS) $ (36.6 ) $ (28.2 ) $ 61.7 $ (33.5 ) $ (36.6 )
Condensed Consolidating Balance Sheets	Rowan Companies plc and Subsidiaries Condensed Consolidating Balance Sheets September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated CURRENT ASSETS: Cash and cash equivalents $ 0.1 $ 14.9 $ 1,017.4 $ — $ 1,032.4 Receivables - trade and other — 1.1 280.4 — 281.5 Prepaid expenses and other current assets 0.4 13.6 17.4 — 31.4 Total current assets 0.5 29.6 1,315.2 — 1,345.3 Property and equipment - gross — 255.4 8,749.6 — 9,005.0 Less accumulated depreciation and amortization — 136.5 2,430.4 — 2,566.9 Property and equipment - net — 118.9 6,319.2 — 6,438.1 Investments in consolidated subsidiaries 5,111.6 6,540.1 — (11,651.7 ) — Due from affiliates 0.2 748.9 33.2 (782.3 ) — Long-term note receivable from unconsolidated subsidiary — — 269.0 — 269.0 Investment in unconsolidated subsidiary — — 34.3 — 34.3 Other assets — 33.3 11.4 — 44.7 $ 5,112.3 $ 7,470.8 $ 7,982.3 $ (12,434.0 ) $ 8,131.4 CURRENT LIABILITIES: Current portion of long-term debt $ — $ 201.1 $ — $ — $ 201.1 Accounts payable - trade 0.6 15.9 95.7 — 112.2 Deferred revenue — — 17.8 — 17.8 Accrued liabilities — 78.5 43.7 — 122.2 Total current liabilities 0.6 295.5 157.2 — 453.3 Long-term debt — 2,309.6 — — 2,309.6 Due to affiliates 18.3 31.7 732.3 (782.3 ) — Other liabilities 4.6 222.9 41.1 — 268.6 Deferred income taxes - net — — 11.1 — 11.1 Shareholders' equity 5,088.8 4,611.1 7,040.6 (11,651.7 ) 5,088.8 $ 5,112.3 $ 7,470.8 $ 7,982.3 $ (12,434.0 ) $ 8,131.4 Rowan Companies plc and Subsidiaries Condensed Consolidating Balance Sheets December 31, 2017 (In millions) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated CURRENT ASSETS: Cash and cash equivalents $ 0.2 $ 206.3 $ 1,125.6 $ — $ 1,332.1 Receivables - trade and other — 1.2 211.6 — 212.8 Prepaid expenses and other current assets 0.3 10.7 4.5 — 15.5 Total current assets 0.5 218.2 1,341.7 — 1,560.4 Property and equipment - gross — 241.9 8,592.0 — 8,833.9 Less accumulated depreciation and amortization — 121.4 2,159.8 — 2,281.2 Property and equipment - net — 120.5 6,432.2 — 6,552.7 Investments in consolidated subsidiaries 5,401.1 6,387.1 — (11,788.2 ) — Due from affiliates 0.2 680.0 11.5 (691.7 ) — Long-term note receivable from unconsolidated subsidiary — — 270.2 — 270.2 Investment in unconsolidated subsidiary — — 30.9 — 30.9 Other assets — 36.4 7.7 — 44.1 $ 5,401.8 $ 7,442.2 $ 8,094.2 $ (12,479.9 ) $ 8,458.3 CURRENT LIABILITIES: Accounts payable - trade $ 0.7 $ 12.9 $ 83.6 $ — $ 97.2 Deferred revenue — — 1.1 — 1.1 Accrued liabilities — 95.7 63.4 — 159.1 Total current liabilities 0.7 108.6 148.1 — 257.4 Long-term debt — 2,510.3 — — 2,510.3 Due to affiliates 11.2 11.4 669.1 (691.7 ) — Other liabilities 3.8 261.2 28.6 — 293.6 Deferred income taxes - net — — 10.9 — 10.9 Shareholders' equity 5,386.1 4,550.7 7,237.5 (11,788.2 ) 5,386.1 $ 5,401.8 $ 7,442.2 $ 8,094.2 $ (12,479.9 ) $ 8,458.3
Consolidating Statements of Cash Flows	Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Cash Flows Nine months ended September 30, 2018 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES $ (4.7 ) $ (139.4 ) $ 31.7 $ — $ (112.4 ) CASH FLOWS FROM INVESTING ACTIVITIES: Capital expenditures — (5.6 ) (111.3 ) — (116.9 ) Purchase of rigs — — (70.8 ) — (70.8 ) Proceeds from disposals of property and equipment — 0.2 7.9 — 8.1 Contributions to consolidated subsidiary for note receivable — (1.9 ) — 1.9 — Investments in consolidated subsidiaries — (5.0 ) — 5.0 — Repayments of note receivable from unconsolidated subsidiary — — 2.3 — 2.3 Net cash used in investing activities — (12.3 ) (171.9 ) 6.9 (177.3 ) CASH FLOWS FROM FINANCING ACTIVITIES: Advances (to) from affiliates 8.5 (39.7 ) 31.2 — — Contributions from issuer — — 5.0 (5.0 ) — Proceeds from borrowings — — 1.9 (1.9 ) — Debt issue costs — — (6.1 ) — (6.1 ) Shares repurchased for tax withholdings on vesting of restricted share units (3.9 ) — — — (3.9 ) Net cash provided by (used in) financing activities 4.6 (39.7 ) 32.0 (6.9 ) (10.0 ) DECREASE IN CASH AND CASH EQUIVALENTS (0.1 ) (191.4 ) (108.2 ) — (299.7 ) CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD 0.2 206.3 1,125.6 — 1,332.1 CASH AND CASH EQUIVALENTS, END OF PERIOD $ 0.1 $ 14.9 $ 1,017.4 $ — $ 1,032.4 Rowan Companies plc and Subsidiaries Condensed Consolidating Statements of Cash Flows Nine months ended September 30, 2017 (In millions) (Unaudited) Rowan plc (Parent) RCI (Issuer) Non-guarantor subsidiaries Consolidating adjustments Consolidated NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES $ (6.1 ) $ 22.0 $ 240.1 $ (15.0 ) $ 241.0 CASH FLOWS FROM INVESTING ACTIVITIES: Capital expenditures — (17.9 ) (60.7 ) — (78.6 ) Proceeds from disposals of property and equipment — 0.9 0.6 — 1.5 Investments in consolidated subsidiaries — 70.7 — (70.7 ) — Investment in unconsolidated subsidiary — — (25.0 ) — (25.0 ) Net cash provided by (used in) investing activities — 53.7 (85.1 ) (70.7 ) (102.1 ) CASH FLOWS FROM FINANCING ACTIVITIES: Advances (to) from affiliates 7.1 (162.2 ) 155.1 — — Distribution to issuer — — (70.7 ) 70.7 — Reductions of long-term debt — (170.0 ) — — (170.0 ) Shares repurchased for tax withholdings on vesting of restricted share units (4.4 ) — — — (4.4 ) Dividends paid — — (15.0 ) 15.0 — Net cash provided by (used in) financing activities 2.7 (332.2 ) 69.4 85.7 (174.4 ) INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS (3.4 ) (256.5 ) 224.4 — (35.5 ) CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD 3.7 532.0 719.8 — 1,255.5 CASH AND CASH EQUIVALENTS, END OF PERIOD $ 0.3 $ 275.5 $ 944.2 $ — $ 1,220.0

Nature of Operations and Basi_3

Nature of Operations and Basis of Presentation (Details) $ / shares in Units, $ in Millions	Oct. 07, 2018$ / shares	Oct. 01, 2018USD ($)drilling_unit	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)$ / d	Mar. 31, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)drilling_unitsegment	Sep. 30, 2017USD ($)	Oct. 16, 2017segment	Dec. 31, 2019USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2017USD ($)
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Number of Operating Segments | segment								3		2
Number of ultra-deepwater drillships | drilling_unit								4
Number of fleet of self-elevating mobile offshore jack-up drilling units | drilling_unit								23
Due from Joint Venture, Total				$ 269				$ 269						$ 271.3
Cumulative effect of new accounting principle in period of adoption				5.5			$ 206.6	5.5	$ 206.6
Demobilization related cash payment								10.7	1.8
REVENUE				192.9			291.6	645.4	986.1
Retained earnings [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative effect of new accounting principle in period of adoption				51.1			$ 206.6	51.1	$ 206.6
Accounting Standards Update 2014-09 [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Demobilization related cash payment						$ 5.5
Accounting Standards Update 2014-09 [Member] | Retained earnings [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative effect of new accounting principle in period of adoption				5.5				5.5
Accounting Standards Update 2016-02 [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Undiscounted future minimum lease commitments				30				30
Estimated present value of future lease commitments				$ 25				$ 25
Saudi Arabia Joint Venture [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Number of fleet of self-elevating mobile offshore jack-up drilling units | drilling_unit								5
Saudi Arabia Joint Venture [Member] | Saudi Aramco [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Equity Method Investment, Ownership Percentage				50.00%				50.00%
Demobilization [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
REVENUE				$ 5.3				$ 5.3
Parent Company [Member] | Saudi Arabia Joint Venture [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Equity Method Investment, Ownership Percentage				50.00%				50.00%
Accounting Standards Update 2018-02 [Member] | Retained earnings [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Cumulative effect of new accounting principle in period of adoption				$ 45.6				$ 45.6
Anadarko [Member] | Rowan Resolute [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Contracts Revenue, Early Termination Of Contract					$ 27.8
Oil and Gas Delivery Commitments and Contracts, Fixed Price | $ / d					418,400
Subsequent Event [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Due from Joint Venture, Total		$ 445
Subsequent Event [Member] | Saudi Arabia Joint Venture [Member] | Saudi Aramco [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Proceeds from Equity Method Investment, Distribution, Return of Capital		$ 90
Subsequent Event [Member] | Parent Company [Member] | Saudi Arabia Joint Venture [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Additional Number Of Rigs Contributed To Joint Venture | drilling_unit		2
Proceeds from Equity Method Investment, Distribution, Return of Capital		$ 90
Subsequent Event [Member] | Ensco [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Shares Received by Rowan Shareholders for Rowan Ensco merge | $ / shares	$ 2.215
Common Stock, Par or Stated Value Per Share | $ / shares	$ 0.10
Scenario, Forecast [Member] | Demobilization [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
REVENUE			$ 1.5								$ 1.7	$ 3.2	$ 8.5

Contract Assets and Contract _3

Contract Assets and Contract Liabilities (Details) - USD ($) $ in Millions	Sep. 15, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2017
Deferred Costs [Abstract]
Contract assets						$ 7.1	$ 2.8
Contract Liabilities [Abstract]
Contract liabilities, current						17.8	1.1
Contract liabilities		$ 38		$ 1.6		38	1.6
Movement in Deferred costs [Rollforward]
Beginning balance				2.8
Plus: contractual additions				4.8
Less: amortization				5.8
Ending balance		1.8		1.8
Demobilization Revenue [Roll Forward]
Beginning balance				0
Plus: contractual additions		5.3
Ending balance		5.3		5.3
Movement in Deferred Revenue [Roll Forward]
Beginning balance				1.6
Plus: contractual additions (1)				45.5
Less: amortization				9.1
Ending balance		$ 38		38
Capex [Member]
Movement in Deferred Revenue [Roll Forward]
Plus: contractual additions (1)				28.6
Deferred Revenue [Member]
Contract Liabilities [Abstract]
Contract liabilities, current						17.8	1.1
Prepaid Expenses and Other Current Assets [Member]
Deferred Costs [Abstract]
Contract assets, current						6.7	2.8
Other Noncurrent Liabilities [Member]
Contract Liabilities [Abstract]
Contract liabilities, noncurrent						20.2	0.5
Other Assets [Member]
Deferred Costs [Abstract]
Contract assets, non-current						$ 0.4	$ 0
Accounts Receivable [Member]
Movement in Deferred Revenue [Roll Forward]
Plus: contractual additions (1)				$ 28.6
RowanReliance [Member] | Cobalt International [Member]
Movement in Deferred Revenue [Roll Forward]
Less: amortization			$ 28.9		$ 57.5
RowanReliance [Member] | Cobalt International [Member] | Deferred Revenue [Member]
Contract Liabilities [Abstract]
Contract liabilities, current	$ 95.9
Contracts Revenue, Early Termination Of Contract	$ 95.9

Contract Assets and Contract _4

Contract Assets and Contract Liabilities Revenue From Contract with Customer (Details) $ in Millions	Sep. 30, 2018USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 months
Revenue, Remaining Performance Obligation, Amount	$ 6.2
Capitalized Contract Cost, Net, Current	$ 0.9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Amount	$ 13.9
Capitalized Contract Cost, Net, Noncurrent	$ 0.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Amount	$ 9.6
Capitalized Contract Cost, Net, Noncurrent	$ 0.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Amount	$ 8.3
Capitalized Contract Cost, Net, Noncurrent	0.1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	38
Capitalized Contract Cost, Net	$ 1.8

Equity Method Investments and_3

Equity Method Investments and Variable Interest Entities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Oct. 17, 2017
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Equity Method Investment, Summarized Financial Information, Revenue	$ 89.2		$ 218.3
Equity Method Investment, Summarized Financial Information, Cost of Sales	51.2		120.5
Equity Method Investment, Summarized Financial Information, Depreciation and Amortization	17		50.4
Equity Method Investment, Summarized Financial Information, Selling, general and administrative expense	6.8		20
Equity Method Investment, Summarized Financial Information, Gain (Loss) on disposal of property, plant and equipment	(1)		0
Equity Method Investment, Summarized Financial Information, Income (Loss) from Continuing Operations	15.2		27.4
Equity Method Investment, Summarized Financial Information, Interest Expense	(5.7)		(16.9)
Equity Method Investment, Summarized Financial Information, Income Tax Expense (benefit)	3.2		3.6
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	6.3		6.9
Equity in earnings of unconsolidated subsidiary	3.1	$ 0	3.4	$ 0
Equity Method Investment, Summarized Financial Information [Abstract]
Equity Method Investment, Summarized Financial Information, Current Assets	205.8		205.8		$ 108.6
Equity Method Investment, Summarized Financial Information, Noncurrent Assets	468.8		468.8		459.7
Equity Method Investment, Summarized Financial Information, Assets	674.6		674.6		568.3
Equity Method Investment, Summarized Financial Information, Current Liabilities	107.4		107.4		29.2
Equity Method Investment, Summarized Financial Information, Noncurrent Liabilities	566.3		566.3		545.1
Equity Method Investment, Summarized Financial Information, Liabilities	673.7		673.7		574.3
Contribution to joint venture						$ 357.7
Due from Joint Venture, Initial Amount						$ 357.7
Due from Joint Venture, Total	269		269		271.3
Long-term note receivable from unconsolidated subsidiary	269		269		270.2
Interest income	8	3.7	22.6	8.9
Revenue from Related Parties	33.4		76.1
Proceeds from disposals of property and equipment			8.1	1.5
Gain (Loss) on Disposition of Property Plant Equipment	$ 1.5	$ 2.8	$ 5	$ 9.3
Saudi Arabia Joint Venture [Member] | Parent Company [Member]
Variable Interest Entity [Line Items]
Equity Method Investment, Ownership Percentage	50.00%		50.00%
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Equity in earnings of unconsolidated subsidiary	$ 3.1		$ 3.4
Equity Method Investment, Summarized Financial Information [Abstract]
Accounts Payable, Related Parties	11.3		11.3		10.8
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure [Abstract]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets	370.3		370.3		319.5
Variable Interest Entity, Nonconsolidated, Carrying Amount, Liabilities	11.3		11.3		10.8
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	359		359		308.7
Accounts Receivable [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Due from Joint Ventures, Current					1.1
Accounts Receivable [Member] | Saudi Arabia Joint Venture [Member] | Parent Company [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Accounts Receivable, Related Parties	59.5		59.5		$ 17.3
Prepaid Expenses and Other Current Assets [Member] | Saudi Arabia Joint Venture [Member] | Parent Company [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Due from Joint Ventures, Current	7.5		7.5
Rig Management Services [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Costs and Expenses, Related Party	9.2		31.8
Secondment Revenue [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Revenue from Related Parties	14.4		36.2
Lease Revenue [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Revenue from Related Parties	8		9.1
Transition Services Revenue [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Revenue from Related Parties	9		26.9
Sales of Supplies [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Revenue from Related Parties	2		3.9
ARO Drilling [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Proceeds from disposals of property and equipment	5.9		7.6
Gain (Loss) on Disposition of Property Plant Equipment	0.9		0.7
ARO Drilling [Member] | Accounts Receivable [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Related Party Transaction, Due from (to) Related Party, Current	6.8		6.8
Purchase of Supplies from Joint Venture [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Costs and Expenses, Related Party	$ 4.4		$ 10.1
Saudi Aramco [Member] | Saudi Arabia Joint Venture [Member]
Variable Interest Entity [Line Items]
Equity Method Investment, Ownership Percentage	50.00%		50.00%
London Interbank Offered Rate (LIBOR) [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Loans Receivable, Basis Spread on Variable Rate						2.00%
Interest Income [Member] | Saudi Arabia Joint Venture [Member] | Parent Company [Member]
Equity Method Investment, Summarized Financial Information [Abstract]
Interest income	$ 2.8		$ 8.4
Operating Segments [Member]
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Equity in earnings of unconsolidated subsidiary	0		0
Operating Segments [Member] | ARO Segment [Member]
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Equity in earnings of unconsolidated subsidiary	$ 0		$ 0

Earnings Per Share (Details)

Earnings Per Share (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares (in shares)	5.5	5.7	5.7	5.6
Share Options and Appreciation Rights [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares (in shares)	1.5	1.7	1.5	1.7
Novested Restricted Shares and Restricted Share Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares (in shares)	4	4	4.2	3.9

Pension and Other Postretirem_3

Pension and Other Postretirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Plan, Plan Amendment [Abstract]
Contribution to pension and other postemployment benefit plans			$ 21.3
Future contributions to pension and other postemployment benefit plans	$ 5.7		5.7
Defined Benefit Pension [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Total net pension cost and other postretirement benefit cost	0.8	$ 2.9	2.1	$ 13.7
Other Postretirement Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Total net pension cost and other postretirement benefit cost	(3)	(2.9)	(8.9)	(8.6)
Direct Operating Costs and Selling General and Administrative | Defined Benefit Pension [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost (1)	0.4	1.2	5.7	9.2
Direct Operating Costs and Selling General and Administrative | Other Postretirement Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost (1)	0	0	0	0.1
Other, Net
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Curtailment gain (2)			(11.4)
Other, Net | Defined Benefit Pension [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost (2)	7.3	6.4	20.7	19.1
Expected return on plan assets (2)	(9.2)	(9.3)	(27.3)	(28.2)
Amortization of net loss (2)	2.4	5.9	16.1	17.4
Amortization of prior service credit (2)	(0.1)	(1.3)	(1.7)	(3.8)
Curtailment gain (2)	0	0	(11.4)	0
Other, Net | Other Postretirement Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost (2)	0.1	0.2	0.4	0.7
Amortization of net loss (2)	0.2	0.2	0.6	0.5
Amortization of prior service credit (2)	$ (3.3)	$ (3.3)	(9.9)	$ (9.9)
Income Taxes [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Provision (benefit) for income tax in Defined Benefit Plan Curtailment			(1.4)
Income Taxes [Member] | Defined Benefit Pension [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Provision (benefit) for income tax in Defined Benefit Plan Curtailment			(1.4)
Other Current Liabilities [Member]
Defined Benefit Plan, Plan Amendment [Abstract]
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment			(1.6)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Settlement			(29.9)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment			0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Increase (Decrease) for Plan Amendment			(31.5)
Accumulated Other Comprehensive Income (Loss) [Member]
Defined Benefit Plan, Plan Amendment [Abstract]
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment			1.3
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Settlement			23.6
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment			(9)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Increase (Decrease) for Plan Amendment			15.9
Other Noncurrent Liabilities [Member]
Defined Benefit Plan, Plan Amendment [Abstract]
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment			0.3
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Settlement			6.3
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment			(1)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Increase (Decrease) for Plan Amendment			$ 5.6

Commitments and Contingent Li_2

Commitments and Contingent Liabilities (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018USD ($)drilling_unit	Dec. 31, 2017USD ($)
Long-term Purchase Commitment [Line Items]
Letters of credit issued	$ 7.7
IRS proposed unfavorable tax adjustments	85
Gross unrecognized tax benefits	98	$ 102
Tax impact of net unrecognized tax benefits, if reversed	$ 35
Saudi Arabia Joint Venture [Member]
Long-term Purchase Commitment [Line Items]
Period Of Joint Venture Funding Of Drilling Rigs	10 years
Saudi Arabia Joint Venture [Member] | Maximum [Member]
Long-term Purchase Commitment [Line Items]
Number Of Drilling Rigs To Be Purchased By Joint Venture | drilling_unit	20
Contingent Funding Obligation To Equity Method Investment	$ 1,250
Number Of Drilling Rigs To Be Purchased By Each Partner in a 12 month period | drilling_unit	3
New Revolving Credit Facility [Member]
Long-term Purchase Commitment [Line Items]
Letters of credit issued	$ 5.4

Share-Based Compensation (Detai

Share-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 27, 2018	Sep. 30, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period for remaining recognition of compensation expense		1 year 9 months
Unrecognized compensation cost related to nonvested share-based compensation arrangements		$ 36.4
Performance Shares [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	36 months
February 27, 2018 Grant [Member] | Restricted Share Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based awards, grant-date fair value	$ 16.6
Weighted-average period for remaining recognition of compensation expense	2 years 8 months 12 days
Awards vesting period	3 years
February 27, 2018 Grant [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based awards, grant-date fair value	$ 6.4
Awards vesting period	3 years
Target value of P-Units (in dollars per unit)	$ 100
February 27, 2018 Grant [Member] | Performance Shares [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected payout on P-Units (in dollars per unit)	$ 0
February 27, 2018 Grant [Member] | Performance Shares [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards vesting period	3 years
Expected payout on P-Units (in dollars per unit)	$ 200
February 27, 2018 Grant [Member] | Performance Shares [Member] | One-Year Period Ending December 31, 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance unit value percentage determined on an annual performance	25.00%
Period for value determination	1 year
February 27, 2018 Grant [Member] | Performance Shares [Member] | One-Year Period Ending December 31, 2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance unit value percentage determined on an annual performance		25.00%
Period for value determination		1 year
February 27, 2018 Grant [Member] | Performance Shares [Member] | One-Year Period Ending December 31, 2020 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance unit value percentage determined on an annual performance		25.00%
Period for value determination		1 year
February 27, 2018 Grant [Member] | Performance Shares [Member] | Three-Year Period Ending December 31, 2020 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period for value determination	3 years
Performance unit value percentage determined on total vesting period performance	25.00%
Other Current Liabilities [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated liabilities for share-based compensation awards classified as short-term		$ 8.5	$ 11.5
Other Noncurrent Liabilities [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated liabilities for share-based compensation awards classified as long-term		$ 5.8	$ 10.5

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - Recurring Basis [Member] - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Inputs, Level 2 [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Long-term Debt, Fair Value	$ 2,250	$ 2,262
Other Assets [Member] | Egypt, Pounds
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Other Assets	1.4	2.2
Other Noncurrent Assets [Member] | Angola, Kwanza
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Other Assets	$ 2.5	$ 4.3

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured on a Recurring and Nonrecurring Basis (Details) - Recurring Basis [Member] - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets - cash equivalents	$ 1,015.7	$ 1,332.1
Egypt, Pounds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	1.4	2.2
Angola, Kwanza
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	2.5	4.3
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets - cash equivalents	1,015.7	1,332.1
Fair Value, Inputs, Level 1 [Member] | Egypt, Pounds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	1.4	2.2
Fair Value, Inputs, Level 1 [Member] | Angola, Kwanza
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	2.5	4.3
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets - cash equivalents	0	0
Fair Value, Inputs, Level 2 [Member] | Egypt, Pounds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
Fair Value, Inputs, Level 2 [Member] | Angola, Kwanza
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets - cash equivalents	0	0
Fair Value, Inputs, Level 3 [Member] | Egypt, Pounds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
Fair Value, Inputs, Level 3 [Member] | Angola, Kwanza
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	$ 0	$ 0

Fair Value Measurements - Other

Fair Value Measurements - Other Fair Value Measurements (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Long-term Debt	$ 2,510.7	$ 2,510.3

Fair Value Measurements - Conce

Fair Value Measurements - Concentration of Credit Risk (Details) - Customer Concentration Risk [Member]	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Deepwater Segment [Member] | Anadarko [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%		19.00%
Deepwater Segment [Member] | Anadarko [Member] | Sales Revenue, Services, Net [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	18.00%	16.00%
Deepwater Segment [Member] | Cobalt International [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%		0.00%
Deepwater Segment [Member] | Cobalt International [Member] | Sales Revenue, Services, Net [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	0.00%	14.00%
Jack-ups and Unallocated and Other [Member] | ARO Drilling [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	23.00%		9.00%
Jack-ups and Unallocated and Other [Member] | ARO Drilling [Member] | Sales Revenue, Services, Net [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	12.00%	0.00%
Jack-ups [Member] | Saudi Aramco [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	43.00%		34.00%
Jack-ups [Member] | Saudi Aramco [Member] | Sales Revenue, Services, Net [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	34.00%	29.00%
Jack-ups [Member] | Shell [Member] | Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	12.00%		0.00%
Jack-ups [Member] | Shell [Member] | Sales Revenue, Services, Net [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	6.00%	0.00%

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Amortization of Net Loss [Member]
Amounts recognized as a component of net periodic pension and other postretirement benefit cost:
Total before income taxes	$ (2.6)	$ (6.1)	$ (16.7)	$ (17.9)
Amortization of Prior Service Credit [Member]
Amounts recognized as a component of net periodic pension and other postretirement benefit cost:
Total before income taxes	3.4	4.6	11.6	13.7
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Amounts recognized as a component of net periodic pension and other postretirement benefit cost:
Total before income taxes	0.8	(1.5)	(5.1)	(4.2)
Income tax (expense) benefit	(0.1)	0.5	1.1	1.5
Total reclassifications for the period, net of income taxes	$ 0.7	$ (1)	$ (4)	$ (2.7)

Other Financial Statement Dis_3

Other Financial Statement Disclosures - Components of Receivables (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Other Financial Statement Disclosures [Abstract]
Trade	$ 260.1	$ 195.8
Income tax	15.1	8
Other	6.3	9
Total receivables - trade and other	$ 281.5	$ 212.8

Other Financial Statement Dis_4

Other Financial Statement Disclosures - Accrued Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Other Financial Statement Disclosures [Abstract]
Pension and other postretirement benefits	$ 10.3	$ 27
Compensation and related employee costs	41.2	69
Interest	39.6	32
Income taxes	13.5	15.4
Other	17.6	15.7
Total accrued liabilities	$ 122.2	$ 159.1

Other Financial Statement Dis_5

Other Financial Statement Disclosures - Long Term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term Debt	$ 2,510.7	$ 2,510.3
Current portion of long-term debt	201.1	0
Long-term Debt, Excluding Current Maturities	2,309.6	2,510.3
Subject Notes [Member] | 7.875% Senior Notes, due August 2019 [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 201.1	$ 200.9
Stated rate	7.875%	7.875%
Principal amount	$ 201.4	$ 201.4
Effective rate	8.00%	8.00%
Subject Notes [Member] | 4.875% Senior Notes, due June 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 624	$ 624.6
Stated rate	4.875%	4.875%
Principal amount	$ 620.8	$ 620.8
Effective rate	4.70%	4.70%
Subject Notes [Member] | 4.75% Senior Notes, due January 2024 [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 396.2	$ 395.9
Stated rate	4.75%	4.75%
Principal amount	$ 398.1	$ 398.1
Effective rate	4.80%	4.80%
Subject Notes [Member] | 7.375% Senior Note Payable Due June 2025 [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 497.8	$ 497.5
Stated rate	7.375%	7.375%
Principal amount	$ 500	$ 500
Effective rate	7.40%	7.40%
Subject Notes [Member] | 5.4% Senior Notes due, December 2042 [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 395.2	$ 395.1
Stated rate	5.40%	5.40%
Principal amount	$ 400	$ 400
Effective rate	5.40%	5.40%
Subject Notes [Member] | 5.85% Senior Notes, due January 2044 [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 396.4	$ 396.3
Stated rate	5.85%	5.85%
Principal amount	$ 400	$ 400
Effective rate	5.90%	5.90%

Other Financial Statement Dis_6

Other Financial Statement Disclosures - Long Term Debt, Narrative (Details) - USD ($) $ in Millions	Feb. 08, 2017	Jan. 03, 2017	Dec. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Jan. 09, 2017
Debt Instrument [Line Items]
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense (Benefit)							$ 61.6		$ 56.7
Long-term Debt				$ 2,510.7			2,510.7		2,510.3
Current portion of long-term debt				201.1			201.1		0
Long-term Debt, Excluding Current Maturities				2,309.6			2,309.6		2,510.3
Letters of credit issued				7.7			7.7
Gain (loss) on extinguishment of debt				0	$ (0.5)		$ 0	$ 1.7
Subject Notes [Member]
Debt Instrument [Line Items]
Debt instrument, face amount of tender offer			$ 750
Early repayment of debt		$ 32.8	490.5
Aggregate amount of debt paid		34.6	463.9
Gain (loss) on extinguishment of debt		2	(33.6)
Payment for Debt Extinguishment or Debt Prepayment Cost			5.9
Debt Instrument Redemption Amount as Percentage of Principal							100.00%
Subject Notes [Member] | 5.85% Senior Notes, due January 2044 [Member]
Debt Instrument [Line Items]
Long-term Debt				396.4			$ 396.4		396.3
Principal amount				400			400		400
Subject Notes [Member] | 7.875% Senior Notes, due August 2019 [Member]
Debt Instrument [Line Items]
Long-term Debt				201.1			201.1		200.9
Early repayment of debt					7
Aggregate amount of debt paid		0.9	186.7		6.5
Gain (loss) on extinguishment of debt					$ (0.5)
Principal amount				201.4			201.4		201.4
Subject Notes [Member] | 4.875% Senior Notes, due June 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt				624			624		624.6
Early repayment of debt						$ 33.5
Aggregate amount of debt paid		33.6	9.8			35.8
Gain (loss) on extinguishment of debt						$ 2.4
Principal amount				620.8			620.8		620.8
Subject Notes [Member] | Senior Note Payable Due September 2017 [Member]
Debt Instrument [Line Items]
Early repayment of debt	$ 94
Aggregate amount of debt paid		$ 0.1	265.5
Gain (loss) on extinguishment of debt	$ (2.1)
Principal amount										$ 92.1
Subject Notes [Member] | 4.75% Senior Notes, due January 2024 [Member]
Debt Instrument [Line Items]
Long-term Debt				396.2			396.2		395.9
Aggregate amount of debt paid			$ 1.9
Principal amount				398.1			398.1		398.1
Subject Notes [Member] | 7.375% Senior Note Payable Due June 2025 [Member]
Debt Instrument [Line Items]
Long-term Debt				497.8			497.8		497.5
Principal amount				500			$ 500		500
Debt Instrument Redemption Amount as Percentage of Principal							101.00%
Existing Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Covenant Terms							The Existing Credit Facility requires the Company to maintain a total debt-to-capitalization ratio of less than or equal to 60%. The Company's consolidated debt to total capitalization ratio
Line of Credit Facility, Letter of Credit Borrowing Capacity				0			$ 0
Availability under Revolving Credit Facility				310.7			310.7
Remaining availability under credit facility				310.7			310.7
Amounts outstanding under credit facility				$ 0			$ 0
Line of Credit Facility, Covenant, Ratio of Indebtedness to Net Capital				33.00%			33.00%
New Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Covenant Terms							The New Credit Agreement contains certain financial covenants applicable to the Company and its subsidiaries, including: (i) a covenant restricting debt to total tangible capitalization to not greater than 55% at the end of each fiscal quarter, (ii) a minimum liquidity requirement of $300 million, (iii) a covenant that the ratio of the net book value of the Company's drilling rigs either marketed or under contract with a customer to the sum of commitments under the New Credit Agreement, the commitments under the Existing Credit Agreement plus any other indebtedness of the borrower and guarantors (other than unsecured intercompany indebtedness that is contractually subordinated to the obligations under the New Credit Agreement) that is secured by a lien, guaranteed by, or has an obligor a subsidiary of the Company, in each case, that directly own or operates a drilling rig, is not less than 3:00 to 1:00 at the end of each fiscal quarter (the "Marketed Rig Value Ratio") and (iv) a covenant that the ratio of (A) the net book value of the Company's drilling rigs, subject to certain exclusions that are directly wholly owned by the Company and its subsidiaries who are borrowers and guarantors under the New Credit Facility to (B) the net book value of all drilling rigs owned by the Company and certain of its local content affiliates, is not less than 80% at the end of each fiscal quarter (the "Guaranteed Rig Value Ratio").
Line of Credit Facility, Letter of Credit Borrowing Capacity				$ 50			$ 50
Availability under Revolving Credit Facility				955			955
Remaining availability under credit facility				949.6			949.6
Amounts outstanding under credit facility				$ 0			$ 0
Line of Credit Facility, Covenant, Ratio of Indebtedness to Net Capital				33.00%			33.00%
Line of Credit Facility, Swingline Borrowing Capacity				$ 129			$ 129
Line of Credit Facility, Restriction				200			200
Letters of credit issued				5.4			5.4
Line of Credit Facility, Covenant, Liquidity				$ 2,292.7			$ 2,292.7
Line of Credit Facility, Covenant, Marketed Rig Value Ratio				4.14			4.14
Line of Credit Facility, Covenant, Guaranteed Rig Value Ratio				84.00%			84.00%
Matures on January 23 2019 | Existing Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Availability under Revolving Credit Facility				$ 60			$ 60
Matures on January 23, 2020 | Existing Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Availability under Revolving Credit Facility				150.7			150.7
Matures on January 23 2021 | Existing Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Availability under Revolving Credit Facility				100			$ 100
Minimum [Member] | Existing Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage							0.125%
Minimum [Member] | New Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage							0.375%
Line of Credit Facility, Covenant, Liquidity				$ 300			$ 300
Line of Credit Facility, Covenant, Marketed Rig Value Ratio				3			3
Line of Credit Facility, Covenant, Guaranteed Rig Value Ratio				80.00%			80.00%
Maximum [Member] | Existing Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage							0.35%
Line of Credit Facility, Covenant, Ratio of Indebtedness to Net Capital				60.00%			60.00%
Maximum [Member] | New Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage							0.70%
Line of Credit Facility, Covenant, Ratio of Indebtedness to Net Capital				55.00%			55.00%
Line of Credit Facility, Additional Borrowing Capacity				$ 250			$ 250
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Existing Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate							1.125%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | New Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate							2.75%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member] | Existing Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate							2.00%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member] | New Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate							4.25%
Base Rate [Member] | Minimum [Member] | Existing Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate							0.125%
Base Rate [Member] | Minimum [Member] | New Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate							1.75%
Base Rate [Member] | Maximum [Member] | Existing Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate							1.00%
Base Rate [Member] | Maximum [Member] | New Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate							3.25%
Foreign Tax Authority [Member]
Debt Instrument [Line Items]
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense (Benefit)							$ 33.7		$ 38.3

Other Financial Statement Dis_7

Other Financial Statement Disclosures - Narrative (Details) $ in Millions	Jan. 05, 2018USD ($)drilling_unit	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Supplemental Cash Flow Information [Line Items]
Number of Rigs Purchased at Auction | drilling_unit	2
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Transition Tax for Accumulated Foreign Earnings, Provisional Income Tax Expense				$ 26.4		$ 34.1
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense (Benefit)				61.6		56.7
Supplemental Cash Flow Information
Accrued capital expenditures				$ 26.5	$ 12.4
Income Taxes
Effective tax rate		(2.50%)	51.00%	(1.80%)	(293.70%)
Provision (benefit) for income taxes		$ 3.5	$ (21.8)	$ 5.8	$ 29.3
Increase (decrease) in income tax expense as compared to prior year periods		$ 25.3		(23.5)
P-59 [Member]
Supplemental Cash Flow Information [Line Items]
Purchase Price of Rigs Won at Auction	38.5
P-60 [Member]
Supplemental Cash Flow Information [Line Items]
Purchase Price of Rigs Won at Auction	38.5
P-59 and P60 Rigs [Member]
Supplemental Cash Flow Information [Line Items]
Purchase Price of Rigs Won at Auction	77
Security Deposit						7.7
Purchase Price of Rigs Won at Auction less Deposit	69.3
Transaction Costs	$ 1.5
Foreign Tax Authority [Member]
Supplemental Cash Flow Information [Line Items]
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense (Benefit)				$ 33.7		$ 38.3

Segment Information (Details)

Segment Information (Details) $ in Millions	3 Months Ended		9 Months Ended		10 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)segment	Sep. 30, 2017USD ($)	Oct. 16, 2017segment
Segment Reporting Information [Line Items]
Number of Operating Segments | segment			3		2
REVENUE	$ 192.9	$ 291.6	$ 645.4	$ 986.1
Operating expenses:
Direct operating costs (excluding items below)	182.3	168.7	516	508.8
Depreciation and amortization	99	103.4	294.3	304
Selling, general and administrative	26.6	24.9	77.4	71.3
Other operating items	1.5	2.8	5	9.3
Equity in earnings of unconsolidated subsidiary	3.1	0	3.4	0
INCOME (LOSS) FROM OPERATIONS	(113.4)	(8.2)	(243.9)	92.7
Deepwater Segment [Member]
Segment Reporting Information [Line Items]
REVENUE	13.9	88.4	131.8	371.8
Jack-ups [Member]
Segment Reporting Information [Line Items]
REVENUE	170	203.2	486.7	614.3
Operating Segments [Member]
Segment Reporting Information [Line Items]
REVENUE	282.1	291.6	863.7	986.1
Operating expenses:
Direct operating costs (excluding items below)	233.5	168.7	636.5	508.8
Depreciation and amortization	116	103.4	344.7	304
Selling, general and administrative	33.4	24.9	97.4	71.3
Other operating items	0.5	2.8	5	9.3
Equity in earnings of unconsolidated subsidiary	0		0
INCOME (LOSS) FROM OPERATIONS	(101.3)	(8.2)	(219.9)	92.7
Operating Segments [Member] | Deepwater Segment [Member]
Segment Reporting Information [Line Items]
REVENUE	13.9	88.4	131.8	371.8
Operating expenses:
Direct operating costs (excluding items below)	48.4	33.2	118.2	117.1
Depreciation and amortization	27.3	27.4	81.2	84.1
Selling, general and administrative	0	0	0	0
Other operating items	0	0	0	0
Equity in earnings of unconsolidated subsidiary	0		0
INCOME (LOSS) FROM OPERATIONS	(61.8)	27.8	(67.6)	170.6
Operating Segments [Member] | Jack-ups [Member]
Segment Reporting Information [Line Items]
REVENUE	170	203.2	486.7	614.3
Operating expenses:
Direct operating costs (excluding items below)	133.9	135.5	397.8	391.7
Depreciation and amortization	71.1	75.3	211.3	217.8
Selling, general and administrative	0	0	0	0
Other operating items	1.5	2.7	5	9.3
Equity in earnings of unconsolidated subsidiary	0		0
INCOME (LOSS) FROM OPERATIONS	(36.5)	(10.3)	(127.4)	(4.5)
Operating Segments [Member] | ARO Segment [Member]
Segment Reporting Information [Line Items]
REVENUE	89.2	0	218.3	0
Operating expenses:
Direct operating costs (excluding items below)	51.2	0	120.5	0
Depreciation and amortization	17	0	50.4	0
Selling, general and administrative	6.8	0	20	0
Other operating items	(1)	0	0	0
Equity in earnings of unconsolidated subsidiary	0		0
INCOME (LOSS) FROM OPERATIONS	15.2	0	27.4	0
Unallocated and other
Segment Reporting Information [Line Items]
REVENUE	9	0	26.9	0
Operating expenses:
Direct operating costs (excluding items below)	0	0	0	0
Depreciation and amortization	0.6	0.7	1.8	2.1
Selling, general and administrative	26.6	24.9	77.4	71.3
Other operating items	0	0.1	0	0
Equity in earnings of unconsolidated subsidiary	0		0
INCOME (LOSS) FROM OPERATIONS	(18.2)	(25.7)	(52.3)	(73.4)
Eliminations and adjustments
Segment Reporting Information [Line Items]
REVENUE	(89.2)	0	(218.3)	0
Operating expenses:
Direct operating costs (excluding items below)	(51.2)	0	(120.5)	0
Depreciation and amortization	(17)	0	(50.4)	0
Selling, general and administrative	(6.8)	0	(20)	0
Other operating items	1	0	0	0
Equity in earnings of unconsolidated subsidiary	3.1		3.4
INCOME (LOSS) FROM OPERATIONS	(12.1)	0	(24)	0
Parent Company [Member] | Saudi Arabia Joint Venture [Member]
Operating expenses:
Equity in earnings of unconsolidated subsidiary	$ 3.1		$ 3.4
Equity Method Investment, Ownership Percentage	50.00%		50.00%
Saudi Arabia | Jack-ups [Member]
Segment Reporting Information [Line Items]
REVENUE	$ 88.8	102.7	$ 270.8	290.2
Saudi Arabia | Unallocated and other
Segment Reporting Information [Line Items]
REVENUE	9	0	26.9	0
Norway | Jack-ups [Member]
Segment Reporting Information [Line Items]
REVENUE	2.3	45.8	65.7	140.9
Trinidad | Jack-ups [Member]
Segment Reporting Information [Line Items]
REVENUE	39.8	30.3	83.1	106.3
United Kingdom | Jack-ups [Member]
Segment Reporting Information [Line Items]
REVENUE	28.8	12.7	50.7	41.9
United States | Deepwater Segment [Member]
Segment Reporting Information [Line Items]
REVENUE	13.9	88.4	131.8	369.4
United States | Jack-ups [Member]
Segment Reporting Information [Line Items]
REVENUE	10.3	11.7	16.4	34.9
Other | Deepwater Segment [Member]
Segment Reporting Information [Line Items]
REVENUE	0	0	0	2.4
Other | Jack-ups [Member]
Segment Reporting Information [Line Items]
REVENUE	$ 0	$ 0	$ 0	$ 0.1
Saudi Aramco [Member] | Saudi Arabia Joint Venture [Member]
Operating expenses:
Equity Method Investment, Ownership Percentage	50.00%		50.00%

Guarantees of Registered Secu_3

Guarantees of Registered Securities - Condensed Consolidating Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2017
Condensed Consolidating Income Statements
REVENUE	$ 192.9	$ 291.6	$ 645.4	$ 986.1
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	182.3	168.7	516	508.8
Depreciation and amortization	99	103.4	294.3	304
Selling, general and administrative	26.6	24.9	77.4	71.3
Loss on disposals of property and equipment	1.5	2.8	5	9.3
Total costs and expenses	309.4	299.8	892.7	893.4
Equity in earnings of unconsolidated subsidiary	3.1	0	3.4	0
INCOME (LOSS) FROM OPERATIONS	(113.4)	(8.2)	(243.9)	92.7
OTHER INCOME (EXPENSE):
Interest expense	(39.2)	(38.5)	(116.6)	(117)
Interest income	8	3.7	22.6	8.9
Gain (loss) on extinguishment of debt	0	(0.5)	0	1.7
Other - net	4	0.8	10.6	3.7
Total other (expense) - net	(27.2)	(34.5)	(83.4)	(102.7)
LOSS BEFORE INCOME TAXES	(140.6)	(42.7)	(327.3)	(10)
Provision (benefit) for income taxes	3.5	(21.8)	5.8	29.3
Equity in earnings (losses) of subsidiaries, net of tax	0	0	0	0
NET LOSS	(144.1)	(20.9)	(333.1)	(39.3)
Statements of Comprehensive Income (Loss)
NET INCOME (LOSS)	(144.1)	(20.9)	(333.1)	(39.3)
OTHER COMPREHENSIVE LOSS:
Net changes in pension and other postretirement plan assets and benefit obligations recognized in other comprehensive income, net of income tax expense of $0 for both the three months ended September 30, 2018 and 2017, and $4.2 and $0 for the nine months ended September 30, 2018 and 2017, respectively (see Note 5).	0	0	15.9	0
Net reclassification adjustment for amounts recognized in net loss as a component of net periodic benefit cost, net of income taxes	(0.7)	1	4	2.7
Total Other Comprehensive Income	(0.7)	1	19.9	2.7
COMPREHENSIVE LOSS	(144.8)	(19.9)	(313.2)	(36.6)
CURRENT ASSETS:
Cash and cash equivalents	1,032.4	1,220	1,332.1	1,255.5	$ 1,032.4	$ 1,332.1
Receivables - trade and other					281.5	212.8
Prepaid expenses and other current assets					31.4	15.5
Total current assets					1,345.3	1,560.4
Property and equipment - gross					9,005	8,833.9
Less accumulated depreciation and amortization					2,566.9	2,281.2
Property and equipment - net					6,438.1	6,552.7
Investment in Consolidated Subsidiary					0	0
Due from affiliates					0	0
Long-term note receivable from unconsolidated subsidiary					269	270.2
Investment in unconsolidated subsidiary					34.3	30.9
Other assets					44.7	44.1
TOTAL ASSETS					8,131.4	8,458.3
CURRENT LIABILITIES:
Current portion of long-term debt					201.1	0
Accounts payable - trade					112.2	97.2
Deferred revenues					17.8	1.1
Accrued liabilities					122.2	159.1
Total current liabilities					453.3	257.4
Long-term debt					2,309.6	2,510.3
Due to affiliates					0	0
Other liabilities					268.6	293.6
Deferred income taxes - net					11.1	10.9
Shareholders' equity					5,088.8	5,386.1
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY					8,131.4	8,458.3
Consolidating Statements of Cash Flows
Net cash provided by (used in) operating activities			(112.4)	241
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures			(116.9)	(78.6)
Purchase of rigs			(70.8)
Proceeds from disposals of property and equipment			8.1	1.5
Contributions to consolidated subsidiary for note receivable			0
Investments in consolidated subsidiaries			0	0
Investment in unconsolidated subsidiary			0	(25)
Repayments of note receivable from unconsolidated subsidiary			2.3	0
Net cash used in investing activities			(177.3)	(102.1)
CASH FLOWS FROM FINANCING ACTIVITIES:
Advances (to) from affiliates			0	0
Distribution to issuer			0	0
Proceeds From Borrowings Net Of Issue Costs			0
Reductions of long-term debt			0	(170)
Debt issue costs			(6.1)	0
Proceeds from exercise of share options			(3.9)	(4.4)
Dividends paid				0
Net cash used in financing activities			(10)	(174.4)
DECREASE IN CASH AND CASH EQUIVALENTS			(299.7)	(35.5)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			1,332.1	1,255.5
CASH AND CASH EQUIVALENTS, END OF PERIOD	1,032.4	1,220	1,032.4	1,220
Consolidating adjustments [Member]
Condensed Consolidating Income Statements
REVENUE	(1.7)	(0.8)	(3.7)	(38.7)
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	0	(3.2)	0	(34.6)
Depreciation and amortization	0	0	0	0.2
Selling, general and administrative	(1.7)	2.4	(3.7)	(4.3)
Loss on disposals of property and equipment	0	0	0	0
Total costs and expenses	(1.7)	(0.8)	(3.7)	(38.7)
Equity in earnings of unconsolidated subsidiary	0		0
INCOME (LOSS) FROM OPERATIONS	0	0	0	0
OTHER INCOME (EXPENSE):
Interest expense	0.5	0.1	1.4	0.4
Interest income	(0.5)	(0.1)	(1.4)	(0.4)
Gain (loss) on extinguishment of debt		0		0
Other - net	0	0	0	0
Total other (expense) - net	0	0	0	0
LOSS BEFORE INCOME TAXES	0	0	0	0
Provision (benefit) for income taxes	0	1	0
Equity in earnings (losses) of subsidiaries, net of tax	102.3	(28.6)	189.4	(30.8)
NET LOSS	102.3	(29.6)	189.4	(30.8)
Statements of Comprehensive Income (Loss)
NET INCOME (LOSS)	102.3	(29.6)	189.4	(30.8)
OTHER COMPREHENSIVE LOSS:
Net changes in pension and other postretirement plan assets and benefit obligations recognized in other comprehensive income, net of income tax expense of $0 for both the three months ended September 30, 2018 and 2017, and $4.2 and $0 for the nine months ended September 30, 2018 and 2017, respectively (see Note 5).			(15.9)
Net reclassification adjustment for amounts recognized in net loss as a component of net periodic benefit cost, net of income taxes	0.7	(1)	(4)	(2.7)
Total Other Comprehensive Income			(19.9)
COMPREHENSIVE LOSS	103	(30.6)	169.5	(33.5)
CURRENT ASSETS:
Cash and cash equivalents	0	0	0	0	0	0
Receivables - trade and other					0	0
Prepaid expenses and other current assets					0	0
Total current assets					0	0
Property and equipment - gross					0	0
Less accumulated depreciation and amortization					0	0
Property and equipment - net					0	0
Investment in Consolidated Subsidiary					(11,651.7)	(11,788.2)
Due from affiliates					(782.3)	(691.7)
Long-term note receivable from unconsolidated subsidiary					0	0
Investment in unconsolidated subsidiary					0	0
Other assets					0	0
TOTAL ASSETS					(12,434)	(12,479.9)
CURRENT LIABILITIES:
Current portion of long-term debt					0
Accounts payable - trade					0	0
Deferred revenues					0	0
Accrued liabilities					0	0
Total current liabilities					0	0
Long-term debt					0	0
Due to affiliates					(782.3)	(691.7)
Other liabilities					0	0
Deferred income taxes - net					0	0
Shareholders' equity					(11,651.7)	(11,788.2)
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY					(12,434)	(12,479.9)
Consolidating Statements of Cash Flows
Net cash provided by (used in) operating activities			0	(15)
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures			0	0
Purchase of rigs			0
Proceeds from disposals of property and equipment			0	0
Contributions to consolidated subsidiary for note receivable			1.9
Investments in consolidated subsidiaries			5	(70.7)
Investment in unconsolidated subsidiary				0
Repayments of note receivable from unconsolidated subsidiary			0
Net cash used in investing activities			6.9	(70.7)
CASH FLOWS FROM FINANCING ACTIVITIES:
Advances (to) from affiliates			0	0
Distribution to issuer			(5)	70.7
Proceeds From Borrowings Net Of Issue Costs			(1.9)
Reductions of long-term debt				0
Debt issue costs			0
Proceeds from exercise of share options			0	0
Dividends paid				15
Net cash used in financing activities			(6.9)	85.7
DECREASE IN CASH AND CASH EQUIVALENTS			0	0
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			0	0
CASH AND CASH EQUIVALENTS, END OF PERIOD	0	0	0	0
Rowan plc (Parent) [Member] | Reportable Legal Entities [Member]
Condensed Consolidating Income Statements
REVENUE	0	0	0	0
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	0	0	0	0
Depreciation and amortization	0	0	0	0
Selling, general and administrative	7.6	7	20.3	18.8
Loss on disposals of property and equipment	0	0	0	0
Total costs and expenses	7.6	7	20.3	18.8
Equity in earnings of unconsolidated subsidiary	0		0
INCOME (LOSS) FROM OPERATIONS	(7.6)	(7)	(20.3)	(18.8)
OTHER INCOME (EXPENSE):
Interest expense	0	0	0	0
Interest income	0	0	0	0
Gain (loss) on extinguishment of debt		0		0
Other - net	5.1	5.1	15.1	15.4
Total other (expense) - net	5.1	5.1	15.1	15.4
LOSS BEFORE INCOME TAXES	(2.5)	(1.9)	(5.2)	(3.4)
Provision (benefit) for income taxes	0	0	0	0
Equity in earnings (losses) of subsidiaries, net of tax	(141.6)	(19)	(327.9)	(35.9)
NET LOSS	(144.1)	(20.9)	(333.1)	(39.3)
Statements of Comprehensive Income (Loss)
NET INCOME (LOSS)	(144.1)	(20.9)	(333.1)	(39.3)
OTHER COMPREHENSIVE LOSS:
Net changes in pension and other postretirement plan assets and benefit obligations recognized in other comprehensive income, net of income tax expense of $0 for both the three months ended September 30, 2018 and 2017, and $4.2 and $0 for the nine months ended September 30, 2018 and 2017, respectively (see Note 5).			15.9
Net reclassification adjustment for amounts recognized in net loss as a component of net periodic benefit cost, net of income taxes	(0.7)	1	4	2.7
Total Other Comprehensive Income			19.9
COMPREHENSIVE LOSS	(144.8)	(19.9)	(313.2)	(36.6)
CURRENT ASSETS:
Cash and cash equivalents	0.1	0.3	0.2	3.7	0.1	0.2
Receivables - trade and other					0	0
Prepaid expenses and other current assets					0.4	0.3
Total current assets					0.5	0.5
Property and equipment - gross					0	0
Less accumulated depreciation and amortization					0	0
Property and equipment - net					0	0
Investment in Consolidated Subsidiary					5,111.6	5,401.1
Due from affiliates					0.2	0.2
Long-term note receivable from unconsolidated subsidiary					0	0
Investment in unconsolidated subsidiary					0	0
Other assets					0	0
TOTAL ASSETS					5,112.3	5,401.8
CURRENT LIABILITIES:
Current portion of long-term debt					0
Accounts payable - trade					0.6	0.7
Deferred revenues					0	0
Accrued liabilities					0	0
Total current liabilities					0.6	0.7
Long-term debt					0	0
Due to affiliates					18.3	11.2
Other liabilities					4.6	3.8
Deferred income taxes - net					0	0
Shareholders' equity					5,088.8	5,386.1
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY					5,112.3	5,401.8
Consolidating Statements of Cash Flows
Net cash provided by (used in) operating activities			(4.7)	(6.1)
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures			0	0
Purchase of rigs			0
Proceeds from disposals of property and equipment			0	0
Contributions to consolidated subsidiary for note receivable			0
Investments in consolidated subsidiaries			0	0
Investment in unconsolidated subsidiary				0
Repayments of note receivable from unconsolidated subsidiary			0
Net cash used in investing activities			0	0
CASH FLOWS FROM FINANCING ACTIVITIES:
Advances (to) from affiliates			8.5	7.1
Distribution to issuer			0	0
Proceeds From Borrowings Net Of Issue Costs			0
Reductions of long-term debt				0
Debt issue costs			0
Proceeds from exercise of share options			(3.9)	(4.4)
Dividends paid				0
Net cash used in financing activities			4.6	2.7
DECREASE IN CASH AND CASH EQUIVALENTS			(0.1)	(3.4)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			0.2	3.7
CASH AND CASH EQUIVALENTS, END OF PERIOD	0.1	0.3	0.1	0.3
RCI (Issuer) [Member] | Reportable Legal Entities [Member]
Condensed Consolidating Income Statements
REVENUE	1.7	0.6	3.7	38.2
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	0	0.4	0	1.2
Depreciation and amortization	0	4.4	0	14.4
Selling, general and administrative	0	0.1	0.5	2
Loss on disposals of property and equipment	(0.7)	(0.1)	(0.1)	1.6
Total costs and expenses	(0.7)	4.8	0.4	19.2
Equity in earnings of unconsolidated subsidiary	0		0
INCOME (LOSS) FROM OPERATIONS	2.4	(4.2)	3.3	19
OTHER INCOME (EXPENSE):
Interest expense	(37.3)	(38.5)	(113.8)	(117.1)
Interest income	0.5	0.9	2.5	2.6
Gain (loss) on extinguishment of debt		(0.5)		1.7
Other - net	(4.5)	(5)	(12.3)	(14.6)
Total other (expense) - net	(41.3)	(43.1)	(123.6)	(127.4)
LOSS BEFORE INCOME TAXES	(38.9)	(47.3)	(120.3)	(108.4)
Provision (benefit) for income taxes	3.8	(0.6)	(3.7)	(10.8)
Equity in earnings (losses) of subsidiaries, net of tax	39.3	47.6	138.5	66.7
NET LOSS	(3.4)	0.9	21.9	(30.9)
Statements of Comprehensive Income (Loss)
NET INCOME (LOSS)	(3.4)	0.9	21.9	(30.9)
OTHER COMPREHENSIVE LOSS:
Net changes in pension and other postretirement plan assets and benefit obligations recognized in other comprehensive income, net of income tax expense of $0 for both the three months ended September 30, 2018 and 2017, and $4.2 and $0 for the nine months ended September 30, 2018 and 2017, respectively (see Note 5).			15.9
Net reclassification adjustment for amounts recognized in net loss as a component of net periodic benefit cost, net of income taxes	(0.7)	1	4	2.7
Total Other Comprehensive Income			19.9
COMPREHENSIVE LOSS	(4.1)	1.9	41.8	(28.2)
CURRENT ASSETS:
Cash and cash equivalents	14.9	275.5	206.3	532	14.9	206.3
Receivables - trade and other					1.1	1.2
Prepaid expenses and other current assets					13.6	10.7
Total current assets					29.6	218.2
Property and equipment - gross					255.4	241.9
Less accumulated depreciation and amortization					136.5	121.4
Property and equipment - net					118.9	120.5
Investment in Consolidated Subsidiary					6,540.1	6,387.1
Due from affiliates					748.9	680
Long-term note receivable from unconsolidated subsidiary					0	0
Investment in unconsolidated subsidiary					0	0
Other assets					33.3	36.4
TOTAL ASSETS					7,470.8	7,442.2
CURRENT LIABILITIES:
Current portion of long-term debt					201.1
Accounts payable - trade					15.9	12.9
Deferred revenues					0	0
Accrued liabilities					78.5	95.7
Total current liabilities					295.5	108.6
Long-term debt					2,309.6	2,510.3
Due to affiliates					31.7	11.4
Other liabilities					222.9	261.2
Deferred income taxes - net					0	0
Shareholders' equity					4,611.1	4,550.7
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY					7,470.8	7,442.2
Consolidating Statements of Cash Flows
Net cash provided by (used in) operating activities			(139.4)	22
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures			(5.6)	(17.9)
Purchase of rigs			0
Proceeds from disposals of property and equipment			0.2	0.9
Contributions to consolidated subsidiary for note receivable			(1.9)
Investments in consolidated subsidiaries			(5)	70.7
Investment in unconsolidated subsidiary				0
Repayments of note receivable from unconsolidated subsidiary			0
Net cash used in investing activities			(12.3)	53.7
CASH FLOWS FROM FINANCING ACTIVITIES:
Advances (to) from affiliates			(39.7)	(162.2)
Distribution to issuer			0	0
Proceeds From Borrowings Net Of Issue Costs			0
Reductions of long-term debt				(170)
Debt issue costs			0
Proceeds from exercise of share options			0	0
Dividends paid				0
Net cash used in financing activities			(39.7)	(332.2)
DECREASE IN CASH AND CASH EQUIVALENTS			(191.4)	(256.5)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			206.3	532
CASH AND CASH EQUIVALENTS, END OF PERIOD	14.9	275.5	14.9	275.5
Non-guarantor subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Consolidating Income Statements
REVENUE	192.9	291.8	645.4	986.6
COSTS AND EXPENSES:
Direct operating costs (excluding items below)	182.3	171.5	516	542.2
Depreciation and amortization	99	99	294.3	289.4
Selling, general and administrative	20.7	15.4	60.3	54.8
Loss on disposals of property and equipment	2.2	2.9	5.1	7.7
Total costs and expenses	304.2	288.8	875.7	894.1
Equity in earnings of unconsolidated subsidiary	3.1		3.4
INCOME (LOSS) FROM OPERATIONS	(108.2)	3	(226.9)	92.5
OTHER INCOME (EXPENSE):
Interest expense	(2.4)	(0.1)	(4.2)	(0.3)
Interest income	8	2.9	21.5	6.7
Gain (loss) on extinguishment of debt		0		0
Other - net	3.4	0.7	7.8	2.9
Total other (expense) - net	9	3.5	25.1	9.3
LOSS BEFORE INCOME TAXES	(99.2)	6.5	(201.8)	101.8
Provision (benefit) for income taxes	(0.3)	(22.2)	9.5	40.1
Equity in earnings (losses) of subsidiaries, net of tax	0	0	0	0
NET LOSS	(98.9)	28.7	(211.3)	61.7
Statements of Comprehensive Income (Loss)
NET INCOME (LOSS)	(98.9)	28.7	(211.3)	61.7
OTHER COMPREHENSIVE LOSS:
Net changes in pension and other postretirement plan assets and benefit obligations recognized in other comprehensive income, net of income tax expense of $0 for both the three months ended September 30, 2018 and 2017, and $4.2 and $0 for the nine months ended September 30, 2018 and 2017, respectively (see Note 5).			0
Net reclassification adjustment for amounts recognized in net loss as a component of net periodic benefit cost, net of income taxes	0	0	0	0
Total Other Comprehensive Income			0
COMPREHENSIVE LOSS	(98.9)	28.7	(211.3)	61.7
CURRENT ASSETS:
Cash and cash equivalents	1,017.4	944.2	1,125.6	719.8	1,017.4	1,125.6
Receivables - trade and other					280.4	211.6
Prepaid expenses and other current assets					17.4	4.5
Total current assets					1,315.2	1,341.7
Property and equipment - gross					8,749.6	8,592
Less accumulated depreciation and amortization					2,430.4	2,159.8
Property and equipment - net					6,319.2	6,432.2
Investment in Consolidated Subsidiary					0	0
Due from affiliates					33.2	11.5
Long-term note receivable from unconsolidated subsidiary					269	270.2
Investment in unconsolidated subsidiary					34.3	30.9
Other assets					11.4	7.7
TOTAL ASSETS					7,982.3	8,094.2
CURRENT LIABILITIES:
Current portion of long-term debt					0
Accounts payable - trade					95.7	83.6
Deferred revenues					17.8	1.1
Accrued liabilities					43.7	63.4
Total current liabilities					157.2	148.1
Long-term debt					0	0
Due to affiliates					732.3	669.1
Other liabilities					41.1	28.6
Deferred income taxes - net					11.1	10.9
Shareholders' equity					7,040.6	7,237.5
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY					$ 7,982.3	$ 8,094.2
Consolidating Statements of Cash Flows
Net cash provided by (used in) operating activities			31.7	240.1
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures			(111.3)	(60.7)
Purchase of rigs			(70.8)
Proceeds from disposals of property and equipment			7.9	0.6
Contributions to consolidated subsidiary for note receivable			0
Investments in consolidated subsidiaries			0	0
Investment in unconsolidated subsidiary				(25)
Repayments of note receivable from unconsolidated subsidiary			2.3
Net cash used in investing activities			(171.9)	(85.1)
CASH FLOWS FROM FINANCING ACTIVITIES:
Advances (to) from affiliates			31.2	155.1
Distribution to issuer			5	(70.7)
Proceeds From Borrowings Net Of Issue Costs			1.9
Reductions of long-term debt				0
Debt issue costs			(6.1)
Proceeds from exercise of share options			0	0
Dividends paid				(15)
Net cash used in financing activities			32	69.4
DECREASE IN CASH AND CASH EQUIVALENTS			(108.2)	224.4
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD			1,125.6	719.8
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 1,017.4	$ 944.2	$ 1,017.4	$ 944.2

Subsequent Event (Details)

Subsequent Event (Details)	Oct. 01, 2018drilling_unit
Parent Company [Member] | Saudi Arabia Joint Venture [Member] | Subsequent Event [Member]
Additional Number Of Rigs Contributed To Joint Venture	2