Ocean Rig UDW 20-F 15 Mar 18 2017 FY Annual report (foreign) Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2017shares
Document And Entity Information [Abstract]
Document Type	20-F
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Entity Registrant Name	Ocean Rig UDW Inc.
Entity Central Index Key	1,447,382
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Trading Symbol	orig
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Well Known Seasoned Issuer	Yes
Entity Common Stock Shares Outstanding	91,567,982
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
CURRENT ASSETS:
Cash and cash equivalents (Note 3)	$ 736,114	$ 718,684
Restricted cash (Note 3)	46,967	34,274
Trade accounts receivable, net of allowance for doubtful receivables (Note 2)	169,651	297,059
Other current assets (Note 5)	37,986	29,924
Total current assets	990,718	1,079,941
FIXED ASSETS, NET:
Advances for drilling units under construction and related costs (Note 6)	0	545,469
Drilling units, machinery and equipment, net (Note 7)	1,852,167	2,438,292
Total fixed assets, net	1,852,167	2,983,761
OTHER NON-CURRENT ASSETS:
Restricted cash (Note 3)	0	20,008
Other non-current assets (Note 8)	9,080	7,834
Total non-current assets, net	9,080	27,842
Total assets	2,851,965	4,091,544
CURRENT LIABILITIES:
Current portion of long-term debt, net of deferred financing costs (Note 9)	81,632	640,557
Due to related parties (Note 4)	726	7,231
Accounts payable and other current liabilities	41,338	53,891
Accrued liabilities	45,018	86,750
Deferred revenue	15,329	23,582
Total current liabilities	184,043	812,011
NON-CURRENT LIABILITIES
Long term debt, net of current portion and deferred financing costs (Note 9)	450,000	3,247,216
Deferred revenue	14,385	19,615
Other non-current liabilities	317	1,952
Total non-current liabilities	464,702	3,268,783
COMMITMENTS AND CONTINGENCIES (Note 17)
STOCKHOLDERS' EQUITY:
Preferred stock, $0.01 par value; 500,000,000 and 100,000,000 shares authorized, at December 31, 2016 and 2017 respectively , nil issued and outstanding at December 31, 2016 and 2017, respectively	0	0
Common stock, $0.01 par value; 1,000,000,000 and 1,800,000,000 shares (1,500,000,000 class A shares and 300,000,000 class B shares) authorized, at December 31, 2016 and December 31, 2017 respectively, 17,486 shares (160,888,606 shares before the 1-for-9,200 reverse stock split) issued and outstanding at December 31, 2016 and 91,567,982 (90,562,138 class A shares and 1,005,844 class B shares) at December 31, 2017 (Note 11)	916	0
Treasury stock; 8,511 shares (78,301,755 shares before the 1-for-9,200 reverse stock split) at $0.01 par value at December 31, 2016 and nil at December 31, 2017 (Note 11)	0	0
Additional paid-in capital	5,722,078	3,525,252
Accumulated other comprehensive income (Note 12)	3,476	3,346
Accumulated deficit	(3,523,250)	(3,517,848)
Total stockholders' equity	2,203,220	10,750
Total liabilities and stockholders' equity	$ 2,851,965	$ 4,091,544

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parentheticals) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Preferred stock par value	$ 0.01	$ 0.01
Preferred stock shares authorized	100,000,000	500,000,000
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Common stock par value	$ 0.01	$ 0.01
Common stock shares authorized	1,800,000,000	1,000,000,000
Common stock shares issued	91,567,982	17,486
Common stock shares outstanding	91,567,982	17,486
Treasury stock, shares	0	8,511
Treasury stock par value		$ 0.01
Before the 1-for-9,200 reverse stock split
Common stock shares issued		160,888,606
Common stock shares outstanding		160,888,606
Treasury stock, shares		78,301,755
Common Class A
Common stock shares authorized	1,500,000,000
Common stock shares issued	90,562,138
Common stock shares outstanding	90,562,138
Common Class B
Common stock shares authorized	300,000,000
Common stock shares issued	1,005,844
Common stock shares outstanding	1,005,844

Consolidated Statement of Opera

Consolidated Statement of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
REVENUES:
Revenues	$ 1,007,520	$ 1,653,667	$ 1,748,200
EXPENSES:
Drilling units operating expenses	295,135	454,329	582,122
Depreciation and amortization	121,193	334,155	362,587
Impairment loss (Note 6 and Note 7)	1,048,828	3,776,338	414,986
General and administrative expenses	73,360	103,961	100,314
Loss on sale of fixed assets	238	25,274	5,177
Legal settlements and other, net (Note 17)	(1,519)	(8,720)	(2,591)
Operating income/ (expenses)	(529,715)	(3,031,670)	285,605
OTHER INCOME/ (EXPENSES):
Interest and finance costs (Note 13)	(248,342)	(226,981)	(280,348)
Interest income	7,442	3,449	9,811
Loss on interest rate swaps (Note 10)	0	(4,388)	(11,513)
Reorganization gain, net (Note 2 and Note 9)	1,029,982	0	0
Loss from issuance of shares upon restructuring (Note 4 and Note 11)	(204,595)	0	0
Gain from repurchase of Senior Notes (Note 9)	0	125,001	189,174
Other, net	3,321	(614)	(12,899)
Total other (expenses)/ income, net	587,808	(103,533)	(105,775)
INCOME / (LOSS) BEFORE INCOME TAXES	58,093	(3,135,203)	179,830
Income taxes (Note 14)	(63,495)	(106,315)	(99,816)
NET INCOME / (LOSS) ATTRIBUTABLE TO OCEAN RIG UDW INC.	(5,402)	(3,241,518)	80,014
NET INCOME / (LOSS) ATTRIBUTABLE TO OCEAN RIG UDW INC. CLASS A AND CLASS B COMMON STOCKHOLDERS (Note 15)	$ (5,402)	$ (3,241,518)	$ 78,839
EARNINGS / (LOSS) PER COMMON SHARE OF CLASS A AND CLASS B ATTRIBUTABLE TO COMMON STOCKHOLDERS, BASIC AND DILUTED (Note 15)	$ (0.21)	$ (307,602.77)	$ 5,227.36
WEIGHTED AVERAGE NUMBER OF CLASS A AND CLASS B COMMON SHARES, BASIC AND DILUTED (Note 15)	25,238,292	10,538	15,082
Dividend declared per Class A and Class B common shares	$ 0	$ 0	$ 3,496
Common Class A
OTHER INCOME/ (EXPENSES):
NET INCOME / (LOSS) ATTRIBUTABLE TO OCEAN RIG UDW INC.	$ (5,366)	$ (3,241,518)	$ 80,014
WEIGHTED AVERAGE NUMBER OF CLASS A AND CLASS B COMMON SHARES, BASIC AND DILUTED (Note 15)	25,070,978	10,538	15,082
Common Class B
OTHER INCOME/ (EXPENSES):
NET INCOME / (LOSS) ATTRIBUTABLE TO OCEAN RIG UDW INC.	$ (36)
WEIGHTED AVERAGE NUMBER OF CLASS A AND CLASS B COMMON SHARES, BASIC AND DILUTED (Note 15)	167,314

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income / (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated Statements of Comprehensive Income / (Loss)
Net income / (loss)	$ (5,402)	$ (3,241,518)	$ 80,014
Other Comprehensive income :
Reclassification of realized losses associated with capitalized interest to the Consolidated Statement of Operations (Note 10)	0	26,187	1,035
Actuarial gains	130	0	62
Total Other Comprehensive income	130	26,187	1,097
Total Comprehensive income / (loss)	$ (5,272)	$ (3,215,331)	$ 81,111

Consolidated Statements of Stoc

Consolidated Statements of Stockholder's Equity - USD ($) $ in Thousands	Total	Treasury Shares	Additional Paid-in Capital	Accumulated Other Comprehensive Income/Loss	Accumulated Deficit	Class A Common Shares	Class B Common Shares
BALANCE, at Dec. 31, 2014	$ 3,166,276	$ 0	$ 3,496,277	$ (23,938)	$ (306,063)	$ 0	$ 0
Balance, shares at Dec. 31, 2014		0				14,347	0
Net income / (loss)	80,014				80,014
Issuance of non-vested shares, shares						33
Issuance of common stock, shares						3,106
Issuance of common stock, value	193,983		193,983			$ 0
Treasury stock, shares		(2,415)
Treasury stock, value	(120,000)		(120,000)
Amortization of stock based compensation	3,676		3,676
Dividends declared and paid	(50,281)				(50,281)
Other comprehensive income	1,097			1,097
BALANCE, at Dec. 31, 2015	3,274,765	$ 0	3,573,936	(22,841)	(276,330)	$ 0	$ 0
Balance, shares at Dec. 31, 2015		(2,415)				17,486	0
Net income / (loss)	(3,241,518)				(3,241,518)
Treasury stock, shares		(6,096)
Treasury stock, value	(49,911)		(49,911)
Amortization of stock based compensation	1,227		1,227
Other comprehensive income	26,187			26,187
BALANCE, at Dec. 31, 2016	10,750	$ 0	3,525,252	3,346	(3,517,848)	$ 0	$ 0
Balance, shares at Dec. 31, 2016		(8,511)				17,486	0
Net income / (loss)	(5,402)				(5,402)
Issuance of common stock, shares						90,663,603	895,404
Issuance of common stock, value	2,197,128		2,196,212			$ 907	$ 9
Conversion of shares, shares converted (Note 11)						(337,533)	(227,093)
Conversion of shares, value (Note 11)						$ (3)	$ (2)
Conversion of shares, shares issued (Note 11)						227,093	337,533
Conversion of shares, value (Note 11)						$ 2	$ 3
Cancellation of treasury stock		8,511				(8,511)
Amortization of stock based compensation	614		614
Other comprehensive income	130			130
BALANCE, at Dec. 31, 2017	$ 2,203,220	$ 0	$ 5,722,078	$ 3,476	$ (3,523,250)	$ 906	$ 10
Balance, shares at Dec. 31, 2017		0				90,562,138	1,005,844

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities:
Net income/ (loss)	$ (5,402)	$ (3,241,518)	$ 80,014
Adjustments to reconcile net income/ (loss) to net cash provided by operating activities:
Depreciation and amortization	121,193	334,155	362,587
Amortization and write-off of financing fees	61,212	21,040	24,033
Amortization income of deferred financing fees	0	0	(2,781)
Change in fair value of derivatives	0	(8,180)	(8,217)
Loss on sale of fixed assets	238	25,274	5,177
Allowance for doubtful receivables	0	0	114,613
Gain from repurchase of senior notes	0	(125,001)	(189,174)
Effect of exchange rate changes on cash	0	0	6,748
Impairment loss	1,048,828	3,776,338	414,986
Reorganization gain - principal debt discharged	(1,129,125)	0	0
Loss from issuance of shares upon restructuring	204,595	0	0
Amortization of stock based compensation	614	1,227	3,676
Changes in operating assets and liabilities:
Trade accounts receivable	127,408	119,045	(188,330)
Other current and non-current assets	(11,176)	73,038	36,027
Due to/ (from) related parties	(6,505)	7,231	(11,287)
Accounts payable and other current and non-current liabilities	(14,058)	(51,048)	19,837
Accrued liabilities	159,029	(31,478)	(56,502)
Deferred revenue	(13,483)	(136,994)	(18,395)
Net Cash Provided by Operating Activities	543,368	763,129	593,012
Cash Flows from Investing Activities:
Advances for drilling units under construction and related costs	(27,693)	(242,990)	(89,867)
Drilling units, machinery, equipment and other improvements/ upgrades	(9,301)	(97,163)	(543,976)
Proceeds/ (loss) from sale of fixed assets	198	(10,850)	300
(Increase)/ decrease in restricted cash	7,315	(41,544)	(10,174)
Net Cash Used in Investing Activities	(29,481)	(392,547)	(643,717)
Cash Flows from Financing Activities:
Proceeds from senior secured credit facility	0	0	462,000
Principal payments and repayments of long-term debt and senior notes	(496,457)	(215,279)	(61,179)
Senior Notes repurchase	0	(121,455)	(273,673)
Net proceeds from common stock issuance	0	0	192,714
Repurchase of common stock	0	(49,911)	0
Dividends paid	0	0	(50,281)
Payment of financing costs, net	0	0	(6,314)
Net Cash Provided by/(Used in) Financing Activities	(496,457)	(386,645)	263,267
Effect of exchange rate changes on cash	0	0	(6,748)
Net increase/(decrease) in cash and cash equivalents	17,430	(16,063)	205,814
Cash and cash equivalents at beginning of year	718,684	734,747	528,933
Cash and cash equivalents at end of year	736,114	718,684	734,747
Cash paid during the years for:
Interest, net of amount capitalized	60,862	254,207	256,056
Income taxes	58,901	70,983	60,687
Reorganization expenses paid	99,144	0	0
Non cash financing and investing activities:
Issuance of non-vested shares	0	0	3
Issuance of common stock under the restructuring	2,197,128	0	0
Proceeds from long-term debt	$ 450,000	$ 0	$ 0

Basis of Presentation and Gener

Basis of Presentation and General Information	12 Months Ended
	Dec. 31, 2017
Basis of Presentation and General Information [Abstract]
Basis of Presentation and General Information	1. Basis of Presentation and General Information: The accompanying consolidated financial statements include the accounts of Ocean Rig UDW Inc., its subsidiaries and consolidated Variable Interest Entities ("VIEs") (collectively, the "Company," "Ocean Rig" or the "Group"). Ocean Rig was formed on December 10, 2007, under the laws of the Republic of the Marshall Islands under the name Primelead Shareholders Inc. as an international contractor of offshore deepwater drilling services. The Company was established by DryShips Inc. ("DryShips" or formerly the "Parent") for the purpose of being the holding company of its drilling segment. DryShips is a publicly listed company on the NASDAQ Capital Market (NASDAQGS: DRYS). On November 24, 2010 and up to December 31, 2016, Ocean Rig UDW had an established office and was registered with the Cypriot Registrar of Companies as an overseas company. On October 6, 2011, the Company's common shares commenced "regular way" trading on the NASDAQ Global Select Market under the ticker symbol "ORIG." On April 5, 2016, the Company purchased all of its shares held by DryShips, through its unrestricted subsidiary, Ocean Rig Investments Inc. (Note 11). After this transaction, DryShips no longer holds any equity interest in the Company. As of April 14, 2016, the corporate domicile of the Company moved from the Republic of the Marshall Islands to the Cayman Islands. On September 11, 2015, the Company entered into an agreement to provide third party technical management services for the offshore drilling unit Cerrado . On April 28, 2016, the Company acquired the drilling unit Cerrado which was renamed to Ocean Rig Paros . On September 22, 2017 and in connection with the restructuring of the Company (the “Restructuring”) and in order to comply with NASDAQ’s listing requirements and meet the minimum bid requirement for continued listing on NASDAQ, the Company commenced trading on a 1-for-9,200 reverse stock split of its issued common shares. All share and per share amounts disclosed in the accompanying consolidated financial statements and notes give effect to the reverse stock split retroactively, for all periods presented. The Company's customers are mainly oil and gas exploration and production companies, including major integrated oil companies, independent oil and gas producers and government-owned oil and gas companies. Customers individually accounting for more than 10% of the Company's revenues during the years ended December 31, 2015, 2016 and 2017, were as follows: Year ended December 31, 2015 2016 2017 Customer A 14 % 11 % - Customer B 19 % 20 % 33% Customer C 13 % - - Customer D 15 % 31 % 40% Customer E 13 % 14 % - Customer F 15 % 18 % - The loss of any of these significant customers could have a material adverse effect on the Company's results of operations if they were not replaced by other customers.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Significant Accounting policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies: (a) Principles of consolidation: The accompanying consolidated financial statements have been prepared in accordance with Generally Accepted Accounting Principles in the United States of America ("US GAAP") and include the accounts and operating results of Ocean Rig UDW, its wholly-owned subsidiaries and its VIEs. A VIE is an entity that in general does not have equity investors with substantive voting rights or that has equity investors that do not provide sufficient financial resources for the entity to support its activities. A controlling financial interest in a VIE is present when a company has the power to direct the activities of a VIE that most significantly impact the entity's economic performance and absorbs a majority of an entity's expected losses, receives a majority of an entity's expected residual returns, or both. All intercompany balances and transactions have been eliminated on consolidation. As of December 31, 2017 and 2016, the Company consolidated one VIE which supports our drilling operation in specific locations, for which it is deemed to be the primary beneficiary, i.e. it has a controlling financial interest in this entity. The VIE's total assets and liabilities, as of December 31, 2016, were $23,227 and $86,119, respectively, while total liabilities exceeded total assets by $62,892. The VIE's total assets and liabilities, as of December 31, 2017, were $15,029 and $92,622, respectively, while total liabilities exceeded total assets by $77,593. As of December 31, 2016 and December 31, 2017, the Company also consolidated one additional VIE due to the Trust (as defined) formed for the purpose of the amendment of the $462,000 Senior Secured Credit Facility (Note 9). Since the assets of the Trust can be used only to settle obligations of the Trust itself and at the same time creditors of the Trust do not have recourse to the general credit of the primary beneficiary, such assets and liabilities are analyzed as follows: December 31, 2016 December 31, 2017 ASSETS CURRENT ASSETS: Cash and cash equivalents $ 167 $ 110 Restricted cash 31,956 45,339 Trade accounts receivable, net 3,341 - Other current assets 1,884 1,929 Total current assets 37,348 47,378 FIXED ASSETS, NET: Drilling units, machinery and equipment, net 675,420 175,362 Total fixed assets, net 675,420 175,362 OTHER NON-CURRENT ASSETS: Restricted cash 20,008 - Total non-current assets, net 20,008 - Total assets $ 732,776 $ 222,740 LIABILITIES AND STOCKHOLDERS' EQUITY CURRENT LIABILITIES: Current portion of long-term debt, net of deferred financing costs $ 164,218 $ 81,632 Accounts payable and other current liabilities 5,218 249 Accrued liabilities 1,791 4,416 Total current liabilities 171,227 86,297 NON-CURRENT LIABILITIES Long term debt, net of current portion and deferred financing costs 82,947 - Total non-current liabilities 82,947 - COMMITMENTS AND CONTINGENCIES - - SHAREHOLDERS' EQUITY: Common stock, $20 par value; 1,000 shares authorized and issued at December 31, 2016 and 2017 20 20 Additional paid-in capital 960 960 Retained earnings 477,622 135,463 Total shareholders' equity 478,602 136,443 Total liabilities and shareholders' equity $ 732,776 $ 222,740 (b) Use of estimates: The preparation of 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 consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. (c) Comprehensive income/ (loss): The Company's comprehensive income/ (loss) is comprised of net income/ (loss), actuarial gains/ losses related to the adoption and implementation of Accounting Standard Codification ("ASC") 715, "Compensation-Retirement Benefits", as well as losses in the fair value of the derivatives that qualify for hedge accounting in accordance with ASC 815 "Derivatives and Hedging" and realized gains/losses on cash flow hedges associated with capitalized interest in accordance with ASC 815-30-35-38 "Derivatives and Hedging". During 2013, the Company adopted the requirements of Accounting Standard Update ("ASU") 2013-02, "Comprehensive Income (Topic 220) - Reporting of Amounts Reclassified out of Accumulated Other Comprehensive Income". The objective of this amendment is to improve the reporting of reclassifications out of accumulated other comprehensive income. The amendments do not change the current requirements for reporting net income or other comprehensive income in financial statements. However, the amendments require an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the statement where net income is presented or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income but only if the amount reclassified is required under US GAAP to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required under US GAAP to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures required under US GAAP that provide additional detail about those amounts. (d) Cash and cash equivalents: The Company considers highly liquid investments such as time deposits and certificates of deposit with an original maturity of three months or less to be cash equivalents. (e) Restricted cash: Restricted cash may include (i) minimum liquidity collateral requirements or minimum required cash deposits, as defined in the Company's loan agreements; (ii) taxes withheld from employees and deposited in designated bank accounts; (iii) amounts pledged as collateral for bank guarantees to suppliers and, (iv) amounts pledged as collateral for credit facilities and swap agreements. (f) Trade accounts receivable net: The amount shown as accounts receivable, trade, at each balance sheet date, includes receivables from customers, net of an allowance for doubtful receivables. At each balance sheet date, all potentially uncollectible accounts are assessed individually for purposes of determining the appropriate allowance for doubtful receivables. As of December 31, 2016 and 2017, the provision for doubtful receivables was $22,368 and $13,526, respectively. (g) Concentration of credit risk: Financial instruments, which potentially subject the Company to significant concentrations of credit risk, consist principally of cash and cash equivalents; trade accounts receivable and derivative contracts (interest rate swaps and foreign currency contracts). The maximum exposure to loss due to credit risk is the book value at the balance sheet date. The Company places its cash and cash equivalents, consisting mostly of bank deposits, with qualified financial institutions. The Company performs periodic evaluations of the relative credit standing of those financial institutions. The Company is exposed to credit risk in the event of non-performance by counter parties to derivative instruments; however, the Company limits its exposure by diversifying among counter parties. When considered necessary, additional arrangements are put in place to minimize credit risk, such as letters of credit or other forms of payment guarantees. The Company limits its credit risk with trade accounts receivable by performing ongoing credit evaluations of its customers' financial condition and generally does not require collateral for its trade accounts receivable . The Company has made advances for the construction of drilling units in a major shipyard in Korea. The ownership of the drilling units is transferred from the yard to the Company at delivery. As of December 31, 2017, cumulative installment payments made to the yard amounted to approximately $466,258 for the two drilling units under construction (Note 6). These installment payments are secured with irrevocable letters of guarantee, or "refund guarantees", issued by financial institutions. (h) Advances for drilling units under construction and related costs: This represents amounts expended by the Company in accordance with the terms of the construction contracts for drilling units as well as other expenses incurred directly or under a management agreement with a related party in connection with onsite supervision. In addition, interest costs incurred during the construction (until the asset is substantially complete and ready for its intended use) are capitalized. The carrying value of drilling units under construction represents the accumulated costs at the balance sheet date. Cost components include payments for yard installments and variation orders, commissions to a related party, construction supervision, equipment, spare parts and capitalized interest. (i) Capitalized interest: Interest expense is capitalized during the construction period of drilling units based on accumulated expenditures for the applicable project at the Company's current rate of borrowing. The amount of interest expense capitalized in an accounting period is determined by applying an interest rate (the "capitalization rate") to the average amount of accumulated expenditures for the asset during the period. The capitalization rates used in an accounting period are based on the rates applicable to borrowings outstanding during the period. The Company does not capitalize amounts in excess of actual interest expense incurred in the period. If the Company's financing plans associate a specific new borrowing with a qualifying asset, the Company uses the rate on that borrowing as the capitalization rate to be applied to that portion of the average accumulated expenditures for the asset that does not exceed the amount of that borrowing. If average accumulated expenditures for the asset exceed the amounts of specific new borrowings associated with the asset, the capitalization rate applied to such excess is a weighted average of the rates applicable to other borrowings of the Company. Capitalized interest expense for the years ended December 31 2015, 2016 and 2017, amounted to $26,055, $28,265 and $27,718, respectively (Note 13). (j) Insurance claims: The Company records insurance claim recoveries for insured losses incurred on damages to fixed assets, loss of hire and for insured crew medical expenses under "Other current assets". Insurance claims are recorded, net of any deductible amounts, at the time the Company's fixed assets suffer insured damages or loss due to the drilling unit being wholly or partially deprived of income as a consequence of damage to the unit or when crew medical expenses are incurred, recovery is probable under the related insurance policies and the Company can make an estimate of the amount to be reimbursed following the insurance claim. (k) Foreign currency translation: The functional currency of the Company is the U.S. Dollar since the Company operates in international drilling markets and therefore, primarily transacts business in U.S. Dollars. The Company's accounting records are maintained in U.S. Dollars. Transactions involving other currencies during the year are converted into U.S. Dollars using the exchange rates in effect at the time of the transactions. At the balance sheet dates, monetary assets and liabilities, which are denominated in other currencies, are translated into U.S. Dollars at the year-end exchange rates. Resulting gains or losses are included in "Other, net" in the accompanying consolidated statements of operations. (l) Long lived assets held for sale: The Company classifies long lived assets and disposal groups as being held for sale in accordance with ASC 360, "Property, Plant and Equipment", when: (i) management has committed to a plan to sell the long lived assets; (ii) the long lived assets are available for immediate sale in their present condition; (iii) an active program to locate a buyer and other actions required to complete the plan to sell the long lived assets have been initiated; (iv) the sale of the long lived assets is probable and transfer of the asset is expected to qualify for recognition as a completed sale within one year; and (v) the long lived assets are being actively marketed for sale at a price that is reasonable in relation to its current fair value and (vi) actions required to complete the plan indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. Long lived assets classified as held for sale are measured at the lower of their carrying amount or fair value less cost to sell. These long lived assets are not depreciated once they meet the criteria to be classified as held for sale. If circumstances arise that previously were considered unlikely and, as a result, the Company decides not to sell a long-lived asset previously classified as held for sale, the asset shall be reclassified as held and used. A long-lived asset that is reclassified shall be measured individually at the lower of its carrying amount before the asset or disposal group was classified as held for sale, adjusted for any depreciation expense that would have been recognized had the asset or disposal group been continuously classified as held and used and its fair value at the date of the subsequent decision not to sell. (m) Drilling units, machinery and equipment, net: Drilling units are stated at historical cost less accumulated depreciation. Such costs include the cost of adding or replacing parts of drilling unit machinery and equipment when the cost is incurred, if the recognition criteria are met. The recognition criteria require that the cost incurred extends the useful life of a drilling unit. The carrying amounts of those parts that are replaced are written off and the cost of the new parts is capitalized. Depreciation is calculated on a straight- line basis over the useful life of the assets after considering the estimated residual value as follows: bare deck 30 years and other asset parts from five to 30 years for the drilling units. Effective January 1, 2017, the Company revised its' residual value estimate for each drilling unit. The Company assessed this residual value based on current and historical market trends. The effect of this change in accounting estimate, which did not require retrospective adoption as per ASC 250 "Accounting Changes and Error Corrections," was to increase net loss for the year ended December 31, 2017 by $14,469 and had also an increase on loss per common share, basic and diluted by $(0.57). (n) Impairment of long-lived assets: The Company reviews for impairment long-lived assets whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. To the extent impairment indicators are present; the Company assesses recoverability of the carrying value of the asset by estimating the undiscounted future net cash flows expected to result from the asset. In developing estimates of future undiscounted cash flows, the Company makes assumptions and estimates about the drilling units future performance, with the significant assumptions being related to drilling rates, fleet utilization, operating expenses, capital expenditures, class survey costs, residual value and the estimated remaining useful life of each drilling unit. The projected net operating cash flows are determined by considering the drilling revenues from existing drilling contracts for the fixed days, while for the unfixed days the Company uses an estimated daily rate equivalent by utilizing available market data. The salvage value used in the impairment test is estimated using the Light Weight Tons (LWT) and the market scrap rate. The remaining significant assumptions used to develop estimates of future undiscounted cash flows are based on historical trends as well as future expectations. Although the Company believes that the assumptions used to evaluate potential impairment are reasonable and appropriate, such assumptions are highly subjective. If the Company's estimate of undiscounted future cash flows for any drilling unit is lower than the carrying value, the carrying value is written down, by recording a charge to operations, to the drilling units' fair market value if the fair market value is lower than the drilling unit's carrying value. The fair market value for the drilling unit is obtained by independent appraisals. For the year ended December 31, 2015, 2016 and 2017, as a result of the impairment review, the Company determined that the carrying amount of two, eight and one units, respectively, was not recoverable and, therefore, a charge of $414,986, $3,658,815 and $473,343, respectively, was recognized and is included in "Impairment loss", in the accompanying consolidated statement of operations (Note 7). In addition, an impairment charge of total advances and related costs provided to the yard, amounting to $92.4 million for the drilling unit under construction Ocean Rig Amorgos (Note 6) and the impairment of $25.2 million relating to the cashflow hedges for interest capitalized on drilling units impaired (Note 10) is included in "Impairment loss" in the consolidated statement of operations. For the year ended December 31, 2017 the Company determined that the full amount of the carrying value of the two drilling units under construction Ocean Rig Crete and Ocean Rig Santorini was not recoverable and, therefore, an impairment charge of $573,162 was recognized and included in the "Impairment loss" in the consolidated statement of operations (Note 6) and a loss of $2,323 due to the reclassification of two drilling units as held and used (previously classified as held for sale) (Note 10 and Note 7) was recognized and included in "Impairment loss", in the consolidated statement of operations. (o) Reorganizations: In accordance with GAAP, the Company has applied ASC 852 "Reorganizations" (ASC 852), in preparing the accompanying consolidated financial statements. ASC 852 requires that the financial statements, for periods subsequent to the Chapter 15 filing, distinguish transactions and events that are directly associated with the reorganization from the ongoing operations of the business. Accordingly, certain revenues, expenses (including professional fees), realized gains and losses and provisions for losses that are realized or incurred in the Chapter 15 proceedings are recorded in reorganization gain, net on the accompanying consolidated statement of operations. Upon emerging from Chapter 15 proceedings on September 22, 2017, the Company did not meet the criteria to qualify for fresh-start reporting. Therefore, the discharge of debt is reported as an extinguishment of debt and classified in accordance with Subtopic 225-20. Non-monetary transactions - exchange of the capital stock of an entity for nonmonetary assets or services : Such transactions are measured at the fair value of the consideration received or the fair value of the equity instruments issued, whichever is more reliably measurable. Any difference between the fair value and the transaction price is considered as gain or loss for the Company. The Company considered as appropriate date to use to measure the fair value of the equity instruments issued, the restructuring effective date and accounts for such transactions in accordance with ASC 845 at fair value of its common shares on that date. (p) Class costs: The Company follows the direct expense method of accounting for periodic class costs incurred during special surveys of drilling units, normally every five years. Class costs and other maintenance costs are expensed in the period incurred and included in "Drilling units operating expenses." (q) Deferred financing costs: Deferred financing costs include fees, commissions and legal expenses associated with the Company's long- term debt. These costs are amortized over the life of the related debt using the effective interest method and are included in interest expense. Unamortized fees relating to loans repaid or refinanced as debt extinguishments are expensed as interest and finance costs in the period the repayment or extinguishment is made. Arrangement fees paid to lenders for loans which the Company has not drawn down are capitalized and included in other current and non-current assets. Amortization and write offs for each of the years ended December 31 2015, 2016 and 2017, amounted to $24,033, $21,040 and $61,212, respectively (Note 13). (r) Revenue and related expenses: Revenues: The Company's services and deliverables are generally sold based upon contracts with customers that include fixed or determinable prices. The Company recognizes revenue when delivery occurs, as directed by its customer, and collectability is reasonably assured. The Company evaluates if there are multiple deliverables within its contracts and whether the agreement conveys the right to use the drilling units for a stated period of time and meets the criteria for lease accounting, in addition to providing a drilling services element, which is generally compensated for by day rates. In connection with drilling contracts, the Company may also receive revenues for preparation and mobilization of equipment and personnel or for capital improvements to the drilling units and day rate or fixed price mobilization and demobilization fees. Revenues are recorded net of agents' commissions. There are two types of drilling contracts: well contracts and term contracts. (i) Well contracts: Well contracts are contracts under which the assignment is to drill a certain number of wells. Revenue from day-rate based compensation for drilling operations is recognized in the period during which the services are rendered at the rates established in the contracts. All mobilization revenues, direct incremental expenses of mobilization and contributions from customers for capital improvements are initially deferred and recognized as revenues and expenses, as applicable, over the estimated duration of the drilling period. To the extent that expenses exceed revenue to be recognized, they are expensed as incurred. Demobilization revenues and expenses are recognized over the demobilization period. All revenues for well contracts are recognized as "Service revenues" in the consolidated statement of operations. (ii) Term contracts: Term contracts are contracts under which the assignment is to operate the unit for a specified period of time. For these types of contracts the Company determines whether the arrangement is a multiple element arrangement containing both a lease element and drilling services element. For revenues derived from contracts that contain a lease, the lease elements are recognized as "Leasing revenues" in the consolidated statement of operations on a basis approximating straight line over the lease period. The drilling services element is recognized as "Service revenues" in the period in which the services are rendered at estimated fair value. Revenues related to the drilling element of mobilization and direct incremental expenses of drilling services are deferred and recognized over the estimated duration of the drilling period. To the extent that expenses exceed revenue to be recognized, they are expensed as incurred. Demobilization fees and expenses are recognized over the demobilization period. Contributions from customers for capital improvements are initially deferred and recognized as revenues over the estimated duration of the drilling contract. Other revenues: Other revenues represent the revenues derived from customer contract terminations. The Company recognizes revenues from contract terminations as it has fulfilled obligations for such terminations and when all contingencies have expired . Reimbursable revenues: Effective January 1, 2017, reimbursements received from the customers for the provision of catering services in accordance with relevant contracts are recorded as revenue. The related costs are recorded as running expenses in the same period. (s) Earnings / (loss) per common share: Basic earnings / (loss) per common share are computed by dividing net income/ (loss) available to common stockholders by the weighted average number of common shares outstanding during the year. Diluted earnings per common share reflect the potential dilution that could occur if securities or other contracts to issue common shares were exercised. Dilution has been computed by the treasury stock method whereby all of the Company's dilutive securities are assumed to be exercised or converted and the proceeds used to repurchase common shares at the weighted average market price of the Company's common shares during the relevant periods. The incremental shares (the difference between the number of shares assumed issued and the number of shares assumed purchased) are included in the denominator of the diluted earnings / (loss) per share computation. (t) Segment reporting: The Company has determined that it operates in one reportable segment, the offshore drilling operations. (u) Financial instruments : The Company designates its derivatives based upon guidance of ASC 815, "Derivatives and Hedging" which establishes accounting and reporting requirements for derivative instruments, including certain derivative instruments embedded in other contracts and for hedging activities. The guidance on accounting for certain derivative instruments and certain hedging activities requires all derivative instruments to be recorded on the balance sheet as either an asset or liability measured at its fair value, with changes in fair value recognized in earnings unless specific hedge accounting criteria are met. As of December 31, 2017 the Company has adopted the provisions of ASU 2016-06 on the Contingent Put and Call Options in Debt Instruments and provided relevant disclosures in Note 9. By this change there is no cumulative effect on the Accumulated Deficit, as of the beginning of the earliest period presented. (i) Hedge accounting: At the inception of a hedge relationship, the Company formally designates and documents the hedge relationship to which the Company wishes to apply hedge accounting and the risk management objective and strategy undertaken for the hedge. The documentation includes identification of the hedging instrument, hedged item or transaction, the nature of the risk being hedged and how the entity will assess the hedging instrument's effectiveness in offsetting exposure to changes in the hedged item's cash flows attributable to the hedged risk. Such hedges are expected to be highly effective in achieving offsetting changes in cash flows and are assessed on an ongoing basis to determine whether they actually have been highly effective throughout the financial reporting periods for which they were designated. The Company is party to interest swap agreements where it receives a floating interest rate and pays a fixed interest rate for a certain period. Contracts which meet the strict criteria for hedge accounting are accounted for as cash flow hedges. A cash flow hedge is a hedge of the exposure to variability in cash flows that is attributable to a particular risk associated with a recognized asset or liability, or a highly probable forecasted transaction that could affect profit or loss. The effective portion of the gain or loss on the hedging instrument is recognized directly as a component of "Accumulated other comprehensive income/ (loss)" in equity, while any ineffective portion, if any, is recognized immediately in current period earnings. The Company discontinues cash flow hedge accounting if the hedging instrument expires and it no longer meets the criteria for hedge accounting or designation is revoked by the Company. At that time, any cumulative gain or loss on the hedging instrument recognized in equity is kept in equity until the forecasted transaction occurs. When the forecasted transaction occurs, any cumulative gain or loss on the hedging instrument is recognized in the consolidated statement of operations. If a hedged transaction is no longer expected to occur, the net cumulative gain or loss recognized in equity is transferred to net profit or loss for the year as financial income or expense. (ii) Other derivatives: Changes in the fair value of derivative instruments that have not been designated as hedging instruments are reported in current period earnings. (v) Fair value measurements: The Company follows the provisions of ASC 820, "Fair Value Measurements and Disclosures" which defines and provides guidance as to the measurement of fair value. ASC 820 creates a hierarchy of measurement and indicates that, when possible, fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. The fair value hierarchy gives the highest priority (Level 1) to quoted prices in active markets and the lowest priority (Level 3) to unobservable data, for example, the reporting entities own data. Under the standard, fair value measurements are separately disclosed by level within the fair value hierarchy (Note 10). (w) Income taxes: Income taxes have been provided for based upon the tax laws and rates in effect in the countries in which the Company's operations are conducted and income is earned. There is no expected relationship between the provision for/or benefit from income taxes and income or loss before income taxes because the countries in which the Company operates have taxation regimes that vary not only with respect to the nominal rate, but also in terms of the availability of deductions, credits and other benefits. Variations also arise because income earned and taxed in any particular country or countries may fluctuate from year to year. Deferred tax assets and liabilities are recognized for the anticipated future tax effects of temporary differences between the financial statement basis and the tax basis of the Company's assets and liabilities using the applicable jurisdictional tax rates in effect at the year in which the asset is realized or the liability settled. A valuation allowance for deferred tax assets is recorded when it is more likely than not that some or all of the benefit from the deferred tax asset will not be realized. As of December 31, 2017 the Company has adopted the provisions of ASU 2015-17 on the Balance Sheet Classification on Deferred Taxes , which requires all deferred tax assets and liabilities, along with any related valuation allowance, be classified as noncurrent on the balance sheet. The new guidance did not impact the consolidated financial statements. The Company accrues interest and penalties related to its liabilities for unrecognized tax benefits as a component of income tax expense. (x) Commitments and contingencies: Provisions are recognized when: the Company has a present legal or constructive obligation as a result of past events; it is probable that an outflow of resources embodying economic benefits will be required to settle the obligation; and a reliable estimate of the amount of the obligation can be made. Provisions are reviewed at each balance sheet date. (y) Stock-based compensation: Stock-based compensation represents vested and non-vested common shares granted to certain employees for their services. The Company calculates total compensation expense for the award based on its fair value on the grant date and amortizes the total compensation on an accelerated basis over the vesting period of the award or service period and recognizes forfeitures as they occur (Note 11). As of December 31, 2017, the Company has adopted the provisions of ASU 2016-09, which did not impact the consolidated financial statements. (z) Inventories: Inventories consist of short term operating supplies held in warehouses which are stated at their historical cost, and consumable bunkers (if any), whose cost is determined by the first in - first out method. Inventories are recorded under "Other Current Assets". In July 2015, the FASB issued ASU No. 2015-11 – Inventory, as part of FASB Simplification Initiative, according to which the entities are required to measure inventory at the lower of cost or net realizable value. Net realizable value is defined as estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. This update was effective for public en

Liquidity and Going Concern con

Liquidity and Going Concern considerations	12 Months Ended
	Dec. 31, 2017
Liquidity and Going Concern considerations [Abstract]
Liquidity and Going Concern considerations	3. Liquidity and Going Concern considerations As at December 31, 2016, the Company had cash and cash equivalents of $718,684, current and non-current restricted cash of $54,282 and positive working capital of $267,930 (working capital is defined as current assets minus current liabilities). The Company's liquidity fluctuates depending on a number of factors, including, among others, revenue efficiency, collection of accounts receivable, debt and interest repayments, as well as payments for operating and general administrative expenses. The prolonged market downturn in offshore drilling industry and the continued depressed outlook, have led to materially lower levels of investing in for offshore exploration and development by the current and potential customers on a global basis, while at the same time supply of available high specification drilling units has increased, which in turn has affected the Company with the early termination of five drilling contracts during the year ended December 31, 2016 and one drilling contract during the year ended December 31, 2017. It also led to the stacking of six drilling units of the Company's fleet as of the date of this report. Considering all the above the Company did not believe that cash on hand following the repayment of the Drill Rigs Senior Notes due in October 2017 and cash generated from operations would be sufficient to meet the maximum leverage ratio covenant requirement for the repayment of the Term B Loan Facilities. As a result, Ocean Rig UDW Inc. and certain of its subsidiaries, Drillships Financing Holding Inc. ("DFH"), Drillships Ocean Ventures Inc. ("DOV") and Drill Rigs Holdings Inc. ("DRH"), which are collectively referred to as the Scheme Companies, have effected schemes of arrangement, or the Schemes, under Section 86 of the Companies Law (2016 Revision) to implement a financial restructuring plan, (the "Restructuring"). On March 23, 2017, the Scheme Companies entered into a Restructuring Support Agreement ("RSA"), with certain creditors of their then-outstanding consolidated indebtedness to implement the Restructuring. Pursuant to the terms of the RSA, the Scheme Companies presented winding up petitions to the Grand Court of the Cayman Islands, on March 24, 2017, and filed applications seeking the appointment of joint provisional liquidators (the "JPLs"), under section 104(3) of the Companies Law (2016) Revision. On March 27, 2017, following a hearing before the Grand Court, the JPLs were appointed in respect to each of the Scheme Companies. The RSA proposed that the Restructuring of each of the Scheme Companies be effected by way of scheme of arrangement under Cayman law. The Schemes provided for substantial deleveraging of the Scheme Companies through an exchange by their creditors or the Scheme Creditors, of approximately $3.7 billion principal amount of debt (plus accrued interest) for new equity of the Company, approximately $288 million in cash (excluding early consent fee) and $450 million of new secured debt. On March 27, 2017, the JPLs as "foreign representatives" of each of the Scheme Companies filed petitions with the U.S. Bankruptcy Court under Chapter 15 of the Bankruptcy Code seeking recognition of the provisional liquidation proceedings and the contemplated Schemes as "foreign main proceedings." On April 3, 2017, the U.S. Bankruptcy Court granted provisional relief extending the protections of the temporary restraining order pending a recognition hearing, which was held on August 16, 2017. Following the recognition hearing, the U.S. Bankruptcy Court granted an order granting recognition to the provisional liquidation proceedings and the Schemes as in the terms sought by the JPLs. On July 20, 2017, the Grand Court gave permission to the Scheme Companies to convene meetings of the Scheme Creditors for the purpose of considering and if thought fit approving the Schemes, or the Schemes Meetings. On August 11, 2017, the Scheme Meetings were held and each of the Schemes was approved by a majority in number of the Scheme Creditors and holding at least 75% in value of claims present and voting at the respective Scheme Meeting. The Schemes were approved by Scheme Creditors holding over 97% of our then-outstanding indebtedness. On August 22, 2017, the JPLs filed an application for an order of the U.S. Bankruptcy Court recognizing and giving full force and effect to the Schemes in the United States. Following the sanction of the Schemes by the Grand Court, a hearing was held before the U.S. Bankruptcy Court on September 20, 2017 to consider the relief requested in the JPLs' application. Shortly after the conclusion of this hearing, the U.S. Bankruptcy Court entered an order giving full force and effect to the Grand Court's orders, the Schemes, and all documents and other agreements related thereto. On August 25, 2017, the U.S. Bankruptcy Court issued a memorandum opinion and an order granting recognition of the provisional liquidation and scheme of arrangement proceedings of the Company and its subsidiaries, DRH, DFH, and DOV pending in the Grand Court of the Cayman Islands as foreign main proceedings, and of the JPLs as the foreign representatives of the Scheme Companies in the United States. If the Schemes were approved by the Cayman Court, the U.S. Bankruptcy Court would conduct a hearing on September 20, 2017, to consider the entry of an order giving full force and effect to the Schemes in the United States. On September 15, 2017, following a hearing held between September 4, 2017 and September 6, 2017, the Grand Court issued orders sanctioning the Schemes. On September 21, 2017, the Company effected a 1-for-9,200 reverse stock split of its common shares. Company's common shares commenced trading on a split-adjusted basis on September 22, 2017. The reverse stock split reduced the number of the issued and outstanding common shares from 82,586,851 shares to approximately 8,975 shares and affected all issued and outstanding common shares. The number of the Company's authorized common shares and the par value and other terms of the common shares were not affected by the reverse stock split. No fractional shares were issued in connection with the reverse stock split. Shareholders of record who would have otherwise been entitled to receive a fractional share as a result of the reverse stock split received a cash payment in lieu thereof. The reverse stock split was completed in connection with the Company’s Restructuring and in order to comply with NASDAQ's listing requirements and meet the minimum bid requirement for continued listing on NASDAQ. On September 22, 2017, referred as the Restructuring Effective Date, the Restructuring took effect. Pursuant to the Schemes, on the Restructuring Effective Date, Scheme Creditors exchanged their existing claims against the respective Scheme Companies for cash, new debt and new equity issued by the Company, as outlined above. The existing claims were either transferred to the Company or released. In particular, Scheme Creditors received shares equivalent to 90.68% of the post-Restructuring equity of the Company and aggregate cash consideration of $320.8 million (including the early consent fee) across all of the Schemes, and the Scheme Companies and certain subsidiaries entered into the New Credit Agreement with the DOV and DFH Scheme Creditors. The New Credit Agreement contains limited restrictive covenants that are usual and customary for facilities of this type. The remaining 9.32% of post-Restructuring equity was issued to Prime Cap Shipping Inc., a company that may be deemed to be beneficially owned by the Company's Chairman , Mr. George Economou, pursuant to the management services agreement with TMS Offshore Services Ltd. as described below . On September 26, 2017, Ocean Rig received formal notice from NASDAQ that the Company had demonstrated compliance with all applicable requirements for the continued listing of the Company's common shares on NASDAQ and confirmed that, as a result of its favorable determination, the Company's common shares will continue to be listed on the Nasdaq Global Select Market. On October 4, 2017, the Grand Court of the Cayman Islands issued an order discharging the JPLs effective as of October 18, 2017. In addition, Lundin Norway AS ("Lundin") has declared their fifth option to extend the existing contract of the Leiv Eiriksson which is now expected to have firm employment up to March 2018. The Company has granted to Lundin two additional options to drill further wells in the future and should Lundin exercise its remaining well options, currently un-declared, the drilling unit could be employed until the middle of 2019. On October 5, 2017, the Company has signed a new drilling contract with Statoil, for one-well drilling program offshore in Tanzania. The contract is expected to commence in the first quarter of 2018 and be performed by the drilling unit Ocean Rig Poseidon. As a result of the above, at December 31, 2017, the Company reported a positive working capital of $806,675 and had cash and cash equivalents of $736,114 and current restricted cash of $46,967. Furthermore, the Company's substantially reduced debt is comprised of two Senior Secured Term Loan Facilities with a maturity date of June 2018 and September, 2024, respectively. The Company, following the Restructuring, expects that it will fund its operations either with cash on hand, cash generated from operations and new bank debt, or a combination thereof, in the twelve-month period ending one year after the accompanying consolidated financial statements. Therefore, there is no substantial doubt about the Company's ability to continue as a going concern, for a reasonable period of time.

Transactions with Related Parti

Transactions with Related Parties	12 Months Ended
	Dec. 31, 2017
Transactions with Related Parties [Abstract]
Transactions with Related Parties	4. Transactions with Related Parties: The amounts included in the accompanying consolidated balance sheets and consolidated statements of operations are as follows: Year ended December 31, 2016 2017 Balance Sheet Advances for drilling units under construction and related costs $ 1,569 $ - Drilling units, machinery and equipment, net 488 - Due to related parties $ (7,231 ) $ (726 ) Accrued liabilities $ (3,100 ) $ (11,786 ) Year ended December 31, Statement of Operations 2015 2016 2017 Revenues – commission fees $ 16,524 $ 14,925 $ 10,342 Drilling units operating expenses $ - $ 4,209 $ 904 Amortization and write-off of financing fees $ 2,781 $ - $ - General and administrative expenses $ 7,409 $ 24,924 $ 26,008 Interest income $ 6,024 $ - $ - Reorganization expenses (including non-cash issuance of shares and other expenses) $ - $ - $ 223,178 TMS Offshore Services Ltd.: On March 31, 2016 and effective from January 1, 2016 and up to September 22, 2017, the Company signed a management services agreement with TMS Offshore Services Ltd. (''TMS"), a company that may be deemed to be beneficially owned by the Company's Chairman, Mr. George Economou, to provide certain management services related to the Company's drilling units including but not limited to commercial, financing, legal and insurance services. Under the terms of this agreement, in January 2017 and effective from January 1, 2017, the Company and TMS agreed to make certain amendments and expand the scope of the agreement. For the year ended December 31, 2017, total charges from TMS under this agreement amounted to $45,521. The Management Services Agreement discussed below, replaced the management services agreement that the Company and its subsidiaries entered into with TMS on March 31, 2016, as amended. On September 22, 2017, the Restructuring Effective Date, as part of the Restructuring, the Company and each of its drilling-unit-owning subsidiaries entered into the Management Services Agreement with TMS to provide certain management services related to the Company's drilling units including but not limited to executive management, commercial, financing, accounting, reporting, information technology, legal, manning, insurance, catering and superintendency services. In consideration for the management services the Company agreed to pay TMS an annual fee of $15,500 (not including reimbursement for certain expenses incurred in connection with their performance of services as manager) plus up to an additional $10,000 based on the satisfaction of certain metrics. The Company will also pay a 1.0% commercial fee on all earnings under any existing drilling contract and any drilling contract entered into after the commencement of the Management Services Agreement. The Company may terminate the Management Services Agreement at any time, subject to the payment of a termination fee of the greater of $150,000, which amount shall be reduced ratably on a daily basis over the term of the Management Services Agreement or $30,000 (the "Convenience Termination Fee"). The Company may also terminate the Management Services Agreement for "cause" upon five business days' notice to TMS, subject to certain conditions, including the Company’s payment to an escrow account of the lesser of $50,000 or the Convenience Termination Fee, due and owing at the time, such funds to be released in accordance with the decision of an appointed arbitrator. A refundable security deposit of $5,000 has been agreed to be placed into an escrow account and if, for any reason, the Company fails to make payments under the Management Services Agreement, then TMS may draw upon such security deposit, until paid in full (Note 8). On December 19, 2017, the Board of Directors approved to pay to TMS the maximum bonus under the previous Management Services Agreement due to the success of the Restructuring. In addition a provision for a maximum bonus on a pro rata basis from September 22, 2017 to December 31, 2017 was accrued, under the new Management Services Agreement. Cardiff Drilling Inc.: Effective January 1, 2013, Ocean Rig Management Inc. ("Ocean Rig Management"), a wholly-owned subsidiary of Ocean Rig entered into a Global Services Agreement with Cardiff Drilling Inc. ("Cardiff Drilling") a company that may be deemed to be beneficially owned by the Chairman, Mr. George Economou, pursuant to which Ocean Rig Management engaged Cardiff Drilling to act as consultant on matters of chartering and sale and purchase transactions for the offshore drilling units operated by the Company. Costs from the Global Services Agreement were expensed in the consolidated statement of operations or capitalized as a component of "Advances for drilling units under construction and related costs" being a directly attributable cost to the construction, as applicable. As of March 31, 2016, the Company terminated the agreement with Cardiff Drilling, at no cost. Vivid Finance Limited: Under the consultancy agreement effective from January 1, 2013, between Ocean Rig Management and Vivid Finance Limited ("Vivid"), a company that may be deemed to be beneficially owned by the Chairman, Mr. George Economou, pursuant to which Vivid acted as a consultant on financing matters for Ocean Rig and its subsidiaries, Vivid provided the Company with financing-related services. As of March 31, 2016, the Company terminated the agreement with Vivid, at no cost. Basset Holdings Inc .: Effective June 1, 2012, the Company entered through one of its' wholly owned subsidiaries into a consultancy agreement with Basset Holdings Inc. ("Basset"), a Marshall Islands company that may be deemed to be beneficially owned by the Company's Executive Vice Chairman, Mr. Anthony Kandylidis, for the provision of his services to the Company. With effect as of December 31, 2016, the Company terminated the agreement with Basset at no cost. Basset is also the owner of 12 (114,286 shares before the 1-for- 9,200 reverse stock split) shares of the Company's common shares, as of December 31, 2017. Steel Wheel Investments Limited: Steel Wheel Investments Limited ("Steel Wheel"), a company that may be deemed to be beneficially owned by the Company's Executive Vice Chairman, Mr. Anthony Kandylidis, is the owner of 170 (1,570,226 shares before the 1-for- 9,200 reverse stock split) shares of the Company's common shares as of December 31, 2017. Prime Cap Shipping Inc.: Prime Cap Shipping Inc. ("Prime Cap") is a Cayman Islands company that may be deemed to be beneficially owned by the Company's Chairman, Mr. George Economou. On September 22, 2017 pursuant to the Restructuring and under the terms of the Management Services Agreement, 8,524,793 common shares of the Company's common shares were issued to Prime Cap (Note 11). As of December 31, 2017 Mr. George Economou, was deemed to beneficially own 8,525,596 common shares (including 8,524,793 shares issued to Prime Cap) representing a 9.3% shareholding of the Company. Azara Services S.A.: Effective January 1, 2013, the Company entered through one of its' wholly owned subsidiaries into a consultancy agreement with Azara Services S.A. ("Azara"), a Marshall Islands company that may be deemed to be beneficially owned by the Company's Chairman, Mr. George Economou, for the provision of the services of the Company's Chief Executive Officer. With effect as of December 31, 2016, the Company terminated the agreement with Azara at no cost. DryShips Inc.: On November 18, 2014, the Company entered into a $120,000 Exchangeable Promissory Note with its former parent company, DryShips. On August 13, 2015, the Company reached an agreement with DryShips and exchanged the outstanding balance owed to the Company under the $120,000 Exchangeable Promissory Note, for 1,932 (17,777,778 shares before the 1-for-9,200 reverse stock split) shares of the Company's shares owned by DryShips. On March 29, 2016, the Company entered into 60 day time charter agreements for the offshore support vessels Crescendo and Jubilee with two subsidiaries of DryShips to assist with the stacking of the Company's drilling units in Las Palmas. On April 5, 2016, the Company's unrestricted subsidiary, Ocean Rig Investments Inc., purchased 6,096 (56,079,533 shares before the 1-for-9,200 reverse stock split) shares of the Company's common shares previously held by DryShips. After this transaction, DryShips no longer holds any equity interest in the Company (Note 11). TMS Tankers Ltd.: During 2016 TMS Tankers Ltd. a company that may be deemed to be beneficially owned by the Company's Chairman, Mr. George Economou, charged the Company for various ad-hoc ancillary services.

Other Current Assets

Other Current Assets	12 Months Ended
	Dec. 31, 2017
Other Current Assets [Abstract]
Other Current Assets	5. Other Current Assets: The amount of other current assets shown in the accompanying consolidated balance sheets is analyzed as follows: December 31, 2016 2017 Inventories $ 12,988 $ 9,573 Deferred mobilization expenses 6,351 6,482 Prepayments and advances 10,500 17,064 Intangible assets, net - 402 Insurance claims - 2,980 Other 85 1,485 Total $ 29,924 $ 37,986

Advances for drilling units und

Advances for drilling units under construction and related costs	12 Months Ended
	Dec. 31, 2017
Advances For Drilling Unit Under Construction And Related Costs [Abstract]
Advances for drilling units under construction and related costs	6. Advances for drilling units under construction and related costs: The amounts shown in the accompanying consolidated balance sheets include milestone payments under the drilling unit building contracts with the shipyards, supervision costs and any material related expenses incurred during the construction periods, all of which are capitalized in accordance with the accounting policy discussed in Note 2. For the years ended December 31, 2016 and 2017, the movement of the advances for drilling units under construction and related costs was as follows: December 31, 2016 2017 Balance at beginning of year $ 394,852 $ 545,469 Advances for drilling units under construction and related costs 242,988 27,693 Impairment loss (advances and related costs for drilling unit under construction) (92,371 ) (573,162) Balance at end of year $ 545,469 $ - As of December 31, 2017, the Company has advanced $309,358 and $156,900 to the yard for the construction of the Ocean Rig Santorini and the Ocean Rig Crete respectively . On August 11, 2016, the Company entered into agreements with the yard to amend certain terms relating to contracts for the construction of its three seventh generation drilling units (the Ocean Rig Santorini , the Ocean Rig Crete and the Ocean Rig Amorgos ) which were previously scheduled for delivery in 2017, 2018 and 2019, respectively . As part of the agreements, the deliveries of the Ocean Rig Santorini and the Ocean Rig Crete were postponed to June 2018 and January 2019, respectively, certain installments were rescheduled and the total construction costs were increased to $694,790 and $709,565, respectively. With respect to the Ocean Rig Santorini , the Company’s subsidiary that holds the shipbuilding contract for the Ocean Rig Santorini has received a notice of default in February 2018 for failure to pay an interim installment, that was due on February 5, 2018 and is currently in commercial discussions with the shipyard to further postpone the delivery of the drilling unit and amend other terms of the shipbuilding contract. Should the Company’s subsidiary that holds the shipbuilding contract and the shipyard fail to renegotiate terms while in default, the contract could be rescinded by the shipyard and all instalment payments paid by us of $309,358 to date could be forfeited. With respect to the Ocean Rig Amorgos, the Company had previously agreed to suspend its construction with an option, subject to the Company's option, to bring it back into force within a period of 18 months after the date of the addendum, which option expired in February 2018. Further to that, as of December 31, 2016, the Company recognized an impairment charge of $92,371 of the total advances and related costs provided to the yard for the Ocean Rig Amorgos which was included in the "Impairment loss", in the accompanying consolidated statements of operations . For the year ended December 31, 2017, as a result of the impairment review, the Company determined that the full amount of the carrying value of the two drilling units under construction Ocean Rig Crete and Ocean Rig Santorini was not recoverable and, therefore, an impairment charge of $573,162 was recognized and included in the "Impairment loss", in the accompanying consolidated statements of operations.

Drilling units, machinery and e

Drilling units, machinery and equipment, net	12 Months Ended
	Dec. 31, 2017
Drilling Units, Machinery And Equipment, Net [Abstract]
Drilling units, machinery and equipment, net	7. Drilling units, machinery and equipment, net: The amounts in the accompanying consolidated balance sheets are analyzed as follows: Cost Accumulated Depreciation Net Book Value Balance December 31, 2015 $ 7,258,995 $ (922,103 ) $ 6,336,892 Additions 99,515 - 99,515 Disposal of assets (7,756 ) 133 (7,623 ) Impairment loss (3,658,815 ) - (3,658,815 ) Depreciation - (331,677 ) (331,677 ) Balance December 31, 2016 $ 3,691,939 (1,253,647 ) 2,438,292 Additions 9,726 - 9,726 Disposal of assets (1,648 ) 1,212 (436 ) Impairment loss (475,666 ) - (475,666 ) Depreciation - (119,749 ) (119,749 ) Balance December 31, 2017 $ 3,224,351 (1,372,184 ) 1,852,167 For the years ended December 31, 2016 and 2017, as a result of the impairment review, the Company determined that the carrying amount of eight and one drilling unit, respectively, were not recoverable and, therefore, a charge of $3,658,815 and $473,343, respectively was recognized and included in the "Impairment loss", in the accompanying consolidated statements of operations in order to write down those drilling units to their fair value. On February 21, 2017, the Company's Board of Directors announced the availability for sale of the Leiv Eiriksson and the Eirik Raude . Consequently, the Company classified the two drilling units as held for sale, as all criteria required for their classification as "Assets held for sale" were met and depreciation for these drilling units was ceased. Effective September 30, 2017, the Company's Board of Directors resolved that the two drilling units, that were previously classified as held for sale, will not be considered as held for sale but held and used. The decision was based upon relevant Company's management recommendation to the Board of Directors, taking into consideration Company's expectations of harsh weather drilling market. The Company reclassified its drilling units as held and used and a loss of $2,323 was recognized and included in "Impairment loss", based on the respective US GAAP guidance, in the accompanying consolidated statement of operations. As of December 31, 2017, all of the Company's drilling units have been pledged as collateral to secure the Company's $450,000 and $462,000 Senior Secured Credit Facilities, as discussed in Note 9.

Other non-current assets

Other non-current assets	12 Months Ended
	Dec. 31, 2017
Other non-current assets [Abstract]
Other non-current assets	8. Other non-current assets: The amount of other non-current assets shown in the accompanying consolidated balance sheets is analyzed as follows: December 31, 2016 2017 Deferred mobilization expenses $ 5,564 $ 4,080 Intangible assets, net 1,845 - Prepaid investments 425 - Security deposit - 5,000 Total $ 7,834 $ 9,080

Long-term Debt

Long-term Debt	12 Months Ended
	Dec. 31, 2017
Long-term Debt [Abstract]
Long-term Debt	9. Long-term Debt: December 31, 2016 December 31, 2017 $1.3 billion Senior Secured Term Loan B Facility $ 1,270,750 $ - $1.9 billion Secured Term Loan B Facility 1,838,250 - $462 million Senior Secured Credit Facility 249,542 81,886 $500 million Senior Unsecured Notes 130,974 - $800 million Senior Secured Notes 459,723 - $450 million Senior Secured Term Loan Facility - 450,000 Less: Deferred financing costs (61,466 ) (254) Total debt 3,887,773 531,632 Less: Current portion (640,557 ) (81,632 ) Long-term portion $ 3,247,216 $ 450,000 7.25% Senior Unsecured Notes due 2019 On March 26, 2014, the Company issued $500,000 aggregate principal amount of 7.25% Senior Unsecured Notes due 2019 (the "$500 million Senior Unsecured Notes"), with a semi-annual coupon interest rate of 7.25% per year. The Company used the net proceeds from the offering, amounting to $493,625, together with cash on hand, to repurchase the outstanding balance of $462,300 under its 9.5% Senior Unsecured Notes. As of December 31, 2016, one of the Company's wholly owned subsidiary, had purchased in the open market an aggregate principal amount of $369,026 of these notes, reducing the then outstanding balance to $130,974. Effective March 21, 2017, these repurchased notes have been cancelled. During the year ended December 31, 2016, the purchase of the notes, resulted in a gain of $57,160 and is included in "Gain from repurchase of senior notes" in the accompanying consolidated statement of operations. 6.50% Senior Secured Notes due 2017 On September 20, 2012, the Company's wholly owned subsidiary DRH (the "Issuer"), issued $800,000 aggregate principal amount of 6.50% Senior Secured Notes due 2017 (the "$800 million Senior Secured Notes"), with a semi-annual coupon interest rate of 6.5% per year. The $800 million Senior Secured Notes were secured by Issuer’s and its subsidiaries’ certain assets, including stocks, and guaranteed by the Company and certain of the existing and future subsidiaries of the Issuer. As of December 31, 2016, two of the Company's wholly owned subsidiaries had purchased in the open market an aggregate principal amount of $148,019, resulting to a gain of $67,841 included in “Gain from repurchase of senior notes” in the accompanying consolidated statements of operations. Effective March 21, 2017, these repurchased notes have been cancelled. $1.3 billion Senior Secured Term Loan B Facility On July 25, 2014, the Company's wholly owned subsidiary, DOV, entered into a $1,300,000 Senior Secured Term Loan B facility (“New Term Loan B facility”) to repay the then outstanding balance of $1,300,000 under the $1,350,000 Senior Secured Credit Facility. The New Term Loan B facility, with a maturity date on July 25, 2021, was secured primarily by first priority mortgages on the drilling units, the Ocean Rig Mylos , the Ocean Rig Skyros and the Ocean Rig Athena and bore a fixed interest rate. $1.9 billion Term Loan B Facility On July 12, 2013, the Company, through its wholly-owned subsidiaries, DFH and Drillships Projects Inc., entered into a $1,800,000 senior secured term loan facility, comprised of two tranches, tranche B-1 of $975,000 (“Tranche B-1”) and tranche B-2 of $825,000 ("Tranche B-2”), collectively, the "$1.9 billion Term Loan B Facility", with respective maturity dates in the first quarter of 2021, subject to adjustment to the third quarter of 2020 in certain circumstances, and the third quarter of 2016. The $1.9 billion Term Loan B Facility was: (i) guaranteed by the Company and certain existing and future subsidiaries of DFH and (ii) secured by certain assets of, and by a pledge of the stock of, DFH and the subsidiary guarantors. On July 26, 2013, the Company through DFH and Drillships Projects Inc. entered into an incremental amendment to the $1,800,000 senior term loan for additional Tranche B-1 in an aggregate principal amount of $100,000. On February 7, 2014, the Company refinanced its then existing short-term Tranche B-2 with a fungible add-on to its existing long-term Tranche B-1 with maturity date at no earlier than the third quarter of 2020. Discharge of the 7.25% Senior Unsecured Notes, 6.50% Senior Secured Notes, $1.3 billion Senior Secured Term Loan B Facility and $1.9 billion Term Loan B Facility On September 22, 2017, the restructuring effective date, the outstanding principal amounts, accrued interest and default interest of the 7.25% Senior Unsecured Notes, $6.50% Senior Secured Notes, $1.3 billion Senior Secured Term Loan B Facility and $1.9 billion Term Loan B Facility were discharged in exchange for new equity in the Company amounting to $1,992,533, cash consideration amounting to $320,800 and the $450 million Senior Secured Term Loan Facility discussed below. The resulted gain amounting to $ 1,129,125 is included as a "Reorganization Gain, net" in the accompanying consolidated statement of operations. Deferred finance fees related to discharged notes and facilities have been written off and are included in "interest and finance costs" in the accompanying consolidated statement of operations. $450 million Senior Secured Term Loan Facility On September 22, 2017 the Company, including certain of its subsidiaries, as borrowers and guarantors, entered into a New Credit Agreement. The New Credit Agreement contains limited restrictive covenants that are usual and customary for facilities of this type, including, without limitation: (i) delivery of financial statements, reports, accountants' letters, certificates and SEC filings; (ii) notices of defaults, material litigation and other material events; (iii) continuation of business and maintenance of existence and material rights and privileges; (iv) compliance with laws, including sanctions laws; and (v) maintenance of property and insurance. The Company and certain of its subsidiaries will guarantee the obligations of the New Credit Agreement and collateral has been granted to the lenders by way of first priority lien over substantially all existing and newly acquired assets of the borrowers and guarantors. The New Credit Agreement consists of a $450,000 Senior Secured Term Loan Facility, bearing interest at 8.00% per annum and with a maturity date of September 20, 2024. In addition, under the terms of the New Credit Agreement, the Company has the option to refinance the facility in full at no cost until March 22, 2018, at 105% from March 23, 2018 until March 22, 2019, at 103% from March 23, 2019 until March 22, 2020 and at 101% from March 23, 2020 until March 22, 2021. Under ASU 2016-06 (Note 2) this option is considered as an embedded call option which has been assessed as closely related to the host contract (the New Credit Agreement), therefore is not valued separately and is not considered a derivative, pursuant to ASC 815 provisions. $462 million Senior Secured Credit Facility On February 13, 2015, the Company's wholly owned subsidiary, Drillship Alonissos Shareholders Inc., entered into a secured term loan facility agreement with a syndicate of lenders and DNB Bank ASA, as facility agent and security agent, for up to $475,000 to partially finance the construction costs of the Ocean Rig Apollo . This facility has a 5 year term and bears interest at LIBOR plus a margin. On March 3, 2015, the Company drew down an amount of $462,000 under this facility. On February 11, 2016, the client of the Ocean Rig Apollo sent to the Company a notice of termination. Under the $462,000 Senior Secured Credit Facility, the Company was required to find a new Satisfactory Drilling Contract (as defined in the loan agreement) by May 21, 2016. The Company did not secure a new drilling contract for the Ocean Rig Apollo and, therefore, was required to make a mandatory prepayment of approximately $145,894 on August 22, 2016. On August 31, 2016, the Company's wholly owned subsidiary, Drillship Alonissos Shareholders Inc., entered into an amendment to the term loan facility agreement in consideration for the lenders agreeing: (i) to reduce the amount of the mandatory prepayment from $145,894 to $125,000;(ii) to release the Company as Guarantor and from all obligations, actual or contingent, joint or several, now or at any time outstanding; (iii) to waive any existing breaches and, (iv) the cold-stacking of the drilling unit. Furthermore, a trust was formed, namely "Drillship Alonissos Stock Trust" (the "Trust"), in which the Company has transferred the shares of Drillship Alonissos Shareholders Inc. together with the shares of Drillship Alonissos Owners Inc., previously held by Drillship Alonissos Shareholders Inc. Additionally, the repayment schedule of the loan was altered to include a cash sweep term authorizing the lenders to transfer any excess cash flow on a monthly basis, as a prepayment pro rata across the loan, therefore, leading to the full repayment of the loan by June 2018, whereas according to the initial repayment schedule it would have been fully repaid by June 2020. Following the repayment, the Trust, will be dissolved and shares will be returned to their initial holders. The Company's outstanding debt is secured by, among other things, first priority mortgages over the Company's operating drilling units, corporate guarantees, first priority assignments of all freights, earnings, insurances and requisition compensation relating to such drilling units and a pledge of the shares of capital stock of certain of the Company's subsidiaries. Certain of our debt instruments contain financial covenants, minimum coverage ratio requirements and minimum liquidity and restrict, without the lender's prior consent, the Company's and its subsidiaries ability to, among other things, pay dividends, change the management and ownership of its drilling units, incur additional indebtedness, incur and create liens on its assets, change in the general nature of the Company's business and require that the Company maintain an established place of business in the United States or the United Kingdom. Total interest and debt amortization cost incurred on long-term debt for the years ended December 31, 2015, 2016 and 2017, amounted to $300,543, $256,222 and $275,494, respectively, of which $26,055, $28,265 and $ 27,718 , respectively, were capitalized as part of the cost of the drilling units under construction. Total interest incurred and amortization of debt issuance cost on long-term debt, net of capitalized interest, are included in "Interest and finance costs" in the accompanying consolidated statement of operations. The Company's weighted average interest rates on the above bank loans and notes were 6.3%, 6.2% and 6.9 %, as of December 31, 2015, 2016, and 2017, respectively. The $462 million and $450 million Senior Secured Credit Facilities are payable in U.S. Dollars and are due on June 2018 and September 2024, respectively. Loan movements for the Company's Senior Unsecured Notes and secured credit facilities throughout 2017, is as follows: Loan Loan Agreement Date Original Amount December 31, 2016 New Loan Discharges/ Repayment December 31, 2017 $800 million Senior Notes September 20, 2012 $ 800,000 459,723 - (459,723 ) $ - $1.9 billion Secured Term Loan B Facility July 12, 2013 1,900,000 1,838,250 - (1,838,250 ) - $500 million Senior Unsecured Notes March 26, 2014 500,000 130,974 - (130,974 ) - $1.3 billion Senior Secured Term Loan B July 25, 2014 1,300,000 1,270,750 - (1,270,750 ) - $462 million Senior Secured Credit Facility February 13, 2015 462,000 249,542 - (167,656 ) 81,886 $ 450 million Senior Secured Term Loan Facility September 22, 2017 450,000 - 450,000 - 450,000 $ 3,949,239 $ 450,000 $ (3,867,353 ) $ 531,886 The annual principal payments required to be made after December 31, 2017, including balloon payments, totaling $531,886 due on June 2018 and September 2024, are as follows: 2018 $ 81,886 2019 - 2020 - 2021 - 2022 - 2023 and thereafter 450,000 Total principal payments 531,886 Less: Financing fees (254 ) Total debt $ 531,632

Financial Instruments and Fair

Financial Instruments and Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Financial Instruments and Fair Value Measurements [Abstract]
Financial Instruments and Fair Value Measurements	10. Financial Instruments and Fair Value Measurements : ASC 815, "Derivatives and Hedging" requires companies to recognize all derivative instruments as either assets or liabilities at fair value in the statement of financial position. The Company recognizes all derivative instruments as either assets or liabilities at fair value on its consolidated balance sheets. Changes in the fair value of derivative instruments that have not been designated as hedging instruments are reported in the accompanying consolidated statement of operations. The Company enters into interest rate swap transactions to manage interest costs and risk associated with changing interest rates with respect to its variable interest rate loans and credit facilities. The Company also enters from time to time into foreign currency forward contracts in order to manage risks associated with fluctuations in foreign currencies. All of the Company's derivative transactions are entered into for risk management purposes. As of December 31, 2015, the Company had seven interest rate swaps outstanding, with a notional amount of $1.6 billion, maturing from April 2016 through November 2017. During the year ended December 31. 2016, the Company terminated the interest rate swaps and there were no interest rate swaps outstanding as of December 31, 2017. Accumulated Other Comprehensive Loss also included realized losses on cash flow hedges associated with interest capitalized during prior years under "Advances for drilling units under construction" amounting to $27,776, which according to ASC 815-30-35 is being reclassified into earnings in the same period or periods during which the hedged forecasted transaction affects earnings. As a result, during the years ended December 31, 2015, 2016 and 2017, amounts of $1,035, $26,187 and nil, respectively, were reclassified into the consolidated statements of operations. The effect of derivative instruments not designated or qualifying as hedging instruments on the Consolidated Statement of Operations is as follows: Amount of Loss Derivatives not designated as hedging instruments Location of Loss Recognized Year ended December 31, 2015 Year ended December 31, 2016 Year ended December 31, 2017 Interest rate swaps Loss on interest rate swaps $ (11,513 ) $ (4,388 ) $ - The carrying amounts of cash and cash equivalents, restricted cash, trade accounts receivable, other current assets and accounts payable and other current liabilities reported in the consolidated balance sheets approximate their respective fair values because of the short-term nature of these accounts. The fair value of credit facilities is estimated based on current rates offered to the Company for similar debt of the same remaining maturities. Additionally, the Company considers its creditworthiness in determining the fair value of the credit facilities. The carrying value approximates the fair market value for floating rate loans. The fair value of the interest rate swaps was determined using a discounted cash flow method based on market-based LIBOR swap yield curves, taking into account current interest rates and the creditworthiness of both the financial instrument counterparty and the Company. The 7.25% Senior Unsecured Notes, the Drill Rigs Senior Notes and the Term Loan B Facilities have a fixed rate and their estimated fair values are determined through Level 2 inputs of the fair value hierarchy (quoted price in the over-the counter market). The $450 million Senior Secured Term Loan Facility has a fixed rate and the estimated fair value was determined through Level 2 inputs of the fair value hierarchy (quoted price in the over-the counter market). The fair value of the $450 million Senior Secured Term Loan Facility at December 31, 2017 was approximately $456 million. The $462 million Senior Secured Credit Facility, has a floating rate on LIBOR and its' carrying value is approximately the same as its' fair market value. The estimated fair value of the above 7.25% Senior Unsecured Notes, Drill Rigs Senior Notes, $1.9 billion Secured Term Loan B Facility and $1.3 billion Senior Secured Term Loan B Facility at December 31, 2015, was approximately $100,367, $357,431, $427,168 and $628,242 respectively. For the aforementioned senior notes and term loans their carrying value net of finance fees as at December 31, 2015, was $226,655, $601,845, $1,814,746 and $1,257,484, respectively. The estimated fair value of the above 7.25% Senior Unsecured Notes, Drill Rigs Senior Notes, $1.9 billion Secured Term Loan B Facility and $1.3 billion Senior Secured Term Loan B Facility at December 31, 2016, was approximately $51,080, $201,129, $1,156,958 and $1,002,304, respectively. For the aforementioned senior notes and term loans their carrying value net of finance fees as at December 31, 2016, was $129,844, $457,745, $1,804,272 and $1,248,747, respectively. The guidance for fair value measurement applies to all assets and liabilities that are being measured and reported on a fair value basis. This guidance enables the reader of the financial statements to assess the inputs used to develop those measurements by establishing a hierarchy for ranking the quality and reliability of the information used to determine fair values. The statement requires that assets and liabilities carried at fair value be classified and disclosed in one of the following three categories. Fair value measurements are classified based upon inputs used to develop the measurement under the following hierarchy: Level 1--Quoted market prices in active markets for identical assets or liabilities. Level 2--Observable market-based inputs or unobservable inputs that are corroborated by market data. Level 3--Unobservable inputs that are not corroborated by market data. The following table summarizes the valuation of assets measured at fair value on a non-recurring basis as of December 31, 2016. Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Impairment loss Non-Recurring measurements: Long-lived assets $ - $ 1,035,499 $ - $ (3,658,815 ) As a result of the impairment analysis performed for the year ended December 31, 2016, the Company's eight drilling units, with a carrying amount of $4,694,314 were written down to their fair value as determined based on the valuations of the independent valuators, resulting in an impairment charge of $3,658,815 which was included in the accompanying consolidated statement of operations for the year ended December 31, 2016 (Note 7), the impairment of $92,371 for the drilling unit under construction Ocean Rig Amorgos (Note 6) and the impairment of $25,152 relating to the cashflow hedges for interest capitalized on drilling units impaired (Note 12). The following table summarizes the valuation of assets measured at fair value on a non-recurring basis as of December 31, 2017. Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Impairment loss Non-Recurring measurements: Long-lived assets $ - $ 234,139 $ - $ (475,666 ) Effective September 30, 2017,one of the Company's drilling units, with a carrying amount of $650,843 was written down to its fair value as determined based on the valuations of the independent valuators, resulting in an impairment charge of $473,343 which was included in the accompanying consolidated statement of operations for the year ended December 31, 2017 (Note 7). Effective September 30, 2017 the Company's Board of Directors resolved that the two drilling units, that were previously classified as held for sale, will not be considered as held for sale but held and used. The Company reclassified its drilling units carrying amount of $56,639 as held and used and a loss of $2,323 was recognized and included in the accompanying consolidated statement of operations (Note 7). The Company also determined that the whole carrying amount of the two drilling units under construction Ocean Rig Crete and Ocean Rig Santorini was not recoverable and, therefore, a charge of $573,162 was recognized and included in the accompanying consolidated statement of operations (Note 6). The fair values of the non-monetary transactions are determined through Level 1 of the fair value hierarchy as defined in FASB guidance for Fair Value Measurements and are derived principally from quoted market prices that allow value to be determined. The fair value of the Company's exchanged capital stock as of the restructuring effective date should be valued by using the share closing price as of that date. As of September 22, 2017, the Company's share closing price was $24.00. The difference between the fair value price as of September 22, 2017 and the consideration price of the common shares issued for the reduction of the principal outstanding balance, accrued interest and default interest of the Company's 7.25% Senior Unsecured Notes, 6.50% Senior Secured Notes, $1.3 billion Senior Secured Term Loan B Facility and $1.9 billion Term Loan B Facility with the Scheme Creditors (Note 9), resulted in a loss and was included in "Reorganization Gain, net" in the accompanying consolidated statement of operations for the year ended December 31, 2017.

Common Stock and Additional Pai

Common Stock and Additional Paid-in Capital	12 Months Ended
	Dec. 31, 2017
Common Stock and Additional Paid-in Capital [Abstract]
Common Stock and Additional Paid-in Capital	11. Common Stock and Additional Paid-in Capital: General On April 24, 2017, the Company's Annual General Meeting of Shareholders (the "Meeting"), approved the increase in the Company's authorized share capital of one billion (1,000,000,000) common shares of a par value of $0.01 each and five hundred million (500,000,000) preferred shares of a par value of $0.01 each to one trillion (1,000,000,000,000) common shares of a par value of $0.01 each and five hundred million (500,000,000) preferred shares of a par value of $0.01 each. On November 3, 2017, an extraordinary general meeting of shareholders, or EGM was held. At the EGM, the shareholders of the Company approved the Second Amended and Restated Memorandum and Articles of Association based on which Company's authorized share capital as this approved on April 24,2017 by the Annual General Meeting of Shareholders, was reduced to one billion eight hundred million (1,800,000,000) common shares, consisting of one billion five hundred million (1,500,000,000) Class A common shares of a par value of $0.01 each, and three hundred million (300,000,000) Class B common shares of a par value of $0.01 each, and one hundred million (100,000,000) preferred shares of par value $0.01 each. Common shares outstanding prior to the adoption of the Second Amended and Restated Memorandum and Articles of Association will remain outstanding and are redesignated as Class A common shares on our register of members. All Company's common shares have equal voting rights and participates equally in dividend distributions. Dividends In March 2015 and in May 2015, the Company paid dividends of $0.19 per common share to its shareholders, with respect to the quarters ended December 31, 2014 and March 31, 2015, respectively. Issuance of common shares On June 8, 2015, the Company successfully completed the offering of 3,106 (28,571,428 shares before the 1-for-9,200 reverse stock split) shares of its common shares, par value $0.01 per share, at a price of $7.00 per share (share price before reverse stock split), resulting in proceeds of $194,134, after deducting placement fees. As part of the offering, Mr. George Economou, the Company's Chairman, purchased $10,000, or 155,299 (1,428,571 before the 1-for-9,200 reverse stock split) shares, of common shares in the offering at the public offering price. On September 22, 2017, upon the occurrence of the restructuring effective date, the Company issued 90,651,603 common shares, par value $0.01 per share, at a price of $24.00 per share resulting in an amount of $1,992,533 issued to the Scheme creditors and $204,595 to Prime Cap, respectively and were recorded in "Common stock" and "Additional paid-in capital" in the accompanying consolidated balance sheets. On November 3, 2017, following the designation of three hundred million (300,000,000) of the Company's common shares as Class B Common Shares the EGM, the Company issued 895,404 Class B Common Shares to certain of shareholders pursuant to the terms of the recently completed financial restructuring. The Class B common shares are convertible into Class A common shares on a one-for-one basis, have equal voting rights and participate equally in dividend distributions and are not and will not be listed on a national securities exchange or a national market system. On November 13, 2017, certain of the Company’s shareholders elected to convert 337,533 Class A Common Shares into 337,533 Class B Common Shares, in accordance with the terms of the Company’s Second Amended and Restated Memorandum and Articles of Association. As of December 31, 2017, the Company's total outstanding common shares amounted to 91,567,982 (Class A Common Shares: 90,562,138 and Class B Common Shares: 1,005,844). Treasury stock During the year ended December 31, 2015, the Company exchanged the $120,000 Exchangeable Promissory Note for an aggregate amount of 2,415 (22,222,222 shares before the 1-for-9,200 reverse stock split) of the Company's shares owned by DryShips (Note 4). These shares were retired on September 21, 2017. On April 5, 2016, the Company's unrestricted subsidiary, Ocean Rig Investments Inc., purchased 6,096 (56,079,533 shares before the 1-for-9,200 reverse stock split) shares of the Company's common shares previously held by DryShips (Note 4). These shares were not retired and are treated as treasury stock for accounting purposes since under U.S. GAAP the parent's shares purchased by a subsidiary are treated as treasury shares. The Company is incorporated in the Cayman Islands. Under Cayman Islands law, shares of a parent company held by a subsidiary company are not characterized as treasury shares, are entitled to vote and be counted in determining the total number of outstanding shares in the Company. These shares were ultimately retired on September 21, 2017. Reverse stock splits On April 24, 2017, the Company's Annual General Meeting of Shareholders, approved a proposal to allow the Company to effect one or more reverse stock splits for ratios ranging from 1-for-2 to not more than 1-for-100,000, with the exact ratio to be set within this range as determined by the Board of Directors or duly constituted committee thereof and any time following the Annual General Meeting of Shareholders. On September 21, 2017, the Company effected a 1-for-9,200 reverse stock split of its common shares. The Company's common shares commenced trading on a split-adjusted basis on September 22, 2017. The reverse stock split was completed in connection with the Company’s Restructuring and in order to comply with NASDAQ's listing requirements and meet the minimum bid requirement for continued listing on NASDAQ. All previously reported share and per share amounts have been restated to reflect the reverse stock split. Restricted stock awards During 2015 and 2016, under the then 2012 Equity Incentive Plan an aggregate of 20 shares (186,702 before the 1-for-9,200 reverse stock split) of non-vested common shares were granted to employees of Ocean Rig. On May 17, 2016, the Company's Compensation Committee approved the discontinuance of the granting of stock awards to the employees of the Company. Following the approval, all the Company's restricted stock awards, apart from those awarded to Azara, were cancelled. On November 14, 2017, the Company’s Board of Directors approved the grant of 4,000 shares of Company’s common shares to each of the three new directors of the Board. The shares vested immediately and were recognized to expenses based on the fair value on the grant date, being $25.56 per share. The 2012 Equity Incentive Plan of the Company was terminated in connection with the Company’s financial restructuring which was completed in September of 2017. A summary of the status of Ocean Rig's non vested shares as of December 31, 2016 and 2017 and movement during the years then ended, is presented below. Number of non vested shares Weighted average grant date fair value per non vested shares Balance December 31, 2015 44 $ 99,360.00 Forfeited (17 ) 92,736.00 Vested (16 ) 114,356.00 Balance December 31, 2016 11 $ 87,032.00 Granted 12,000 25.56 Vested (12,011) 105.24 Balance December 31, 2017 - $ - Number of vested shares Weighted average grant date fair value per vested shares As at December 31, 2015 66 $ 139,380.00 Vested shares granted in prior years 16 114,356.00 Granted and vested shares in prior years, but cancelled during 2016 (45 ) 124,384.00 As at December 31, 2016 37 $ 146,648.00 Vested shares granted in prior years 11 87,032.00 Vested shares granted in 2017 12,000 25.56 As at December 31, 2017 12,048 $ 558.94 As of December 31, 2015, 2016 and 2017, there was $2,299, $314 and nil, respectively, of total unrecognized compensation cost related to non-vested share-based compensation arrangements granted by the Company, respectively. The amounts of $3,676, $1,506 and $314 represent the stock based compensation expense which are recorded in "General and administrative expenses", in the accompanying consolidated statements of operations for the years ended December 31, 2015, 2016 and 2017, respectively. That cost of $314 relating to the Company’s restricted stock award, entitled to Azara, was fully recognized as at December 31, 2017.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Accumulated Other Comprehensive Income	12. Accumulated Other Comprehensive Income: The amounts in the accompanying balance sheets are analyzed as follows: December 31, 2016 2017 Actuarial pension gain 3,346 3,476 Total $ 3,346 $ 3,476

Interest and Finance Costs

Interest and Finance Costs	12 Months Ended
	Dec. 31, 2017
Interest and Finance Costs [Abstract]
Interest and Finance Costs	13. Interest and Finance Costs: The amounts in the accompanying consolidated statements of operations are analyzed as follows: December 31, 2015 2016 2017 Interest costs on long term debt $ 276,510 $ 235,182 $ 214,282 Amortization and write off of financing fees 24,033 21,040 61,212 Discount on receivable from drilling contract 3,018 (2,821) (308 ) Capitalized borrowing costs (26,055 ) (28,265 ) (27,718 ) Commissions, commitment fees and other financial expenses 2,842 1,845 874 Total $ 280,348 $ 226,981 $ 248,342

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Taxes [Abstract]
Income Taxes	14. Income Taxes: Ocean Rig UDW is subject to Cayman Islands tax which is zero and operates through its various subsidiaries in a number of countries throughout the world. Therefore the Company may pay tax within some jurisdictions even though it might have losses in others. Income taxes have been provided based upon the laws and rates in effect in the countries in which our operations are conducted or in which our subsidiaries are considered residents for income tax purposes. The Company’s income tax expense or benefit arises from our mix of pre-tax earnings or losses, respectively, in the international tax jurisdictions in which we operate. Since the countries in which operates in have different statutory tax rates and tax regimes with respect to one another there is no expected relationship between the provision for income taxes and income or loss before income taxes. A loss in one jurisdiction may not be offset against taxable income in another jurisdiction. The components of the Company's income/ (losses) before taxes, after adjusting for impairment losses and gains from repurchases of senior notes, are as follows: Year ended December 31 2015 2016 2017 Domestic income/ (loss) (Marshall Islands/ Cayman Islands) $ 219,900 $ 126,244 $ - Foreign income 185,742 93,633 - Domestic (loss)/ income (Cayman Islands) - (97,939) (276,471 ) Foreign income - 394,196 558,005 Total income before taxes, excluding impairment loss, gain from repurchases of senior notes, reorganization gain, net and loss from issuance of shares upon restructuring $ 405,642 $ 516,134 $ 281,534 The components of the Company's tax expense were as follows: Year Ended December 31, 2015 2016 2017 Current Tax expense $ 99,816 $ 106,315 $ 63,495 Deferred Tax expense - - - Income taxes $ 99,816 $ 106,315 $ 63,495 Effective tax rate on income / (loss) excluding impairment loss and gain from repurchase of the senior secured notes 24.6 % 20.6 % 22.6 % In 2017, approximately 92% of the current tax expense related to taxes Angola, Brazil and Congo, in 2016, approximately 93% of the current tax expense related to taxes in Angola, Brazil, Norway, Congo and Senegal and in 2015, approximately 90% of the current tax expense related to taxes in Angola, Brazil, Norway and Congo. Taxes have not been reflected in other comprehensive income/ (loss) since the valuation allowances would not result in the recognition of deferred tax. A reconciliation between the statutory tax rate to the effective tax rate is as follows: Year Ended December 31, Reconciliation of total tax expense: 2015 2016 2017 Income tax 94,331 106,315 63,495 Taxes on litigation matters subject to statutory rates, including interest and penalties 5,485 - - Total $ 99,816 $ 106,315 $ 63,495 Ocean Rig has elected to use the statutory tax rate for each year based upon the location where the largest parts of its operations were domiciled. During 2015, 2016 and 2017, most of its activities were in the Republic of the Marshall Islands, and Cayman Island (from April 2016) with a tax rate of zero. On April 14, 2016, the corporate domicile of the Company moved from Republic of the Marshall Islands to the Cayman Islands. Ocean Rig is subject to changes in tax laws, treaties, regulations and interpretations in and between the countries in which its subsidiaries operate. A material change in these tax laws, treaties, regulations and interpretations could result in a higher or lower effective tax rate on worldwide earnings. As of December 31, 2016 and 2017, the current liability for corporate income tax amounts to $8,991 and $10,994, respectively and is included in “Accounts payable and other current liabilities” in the accompanying consolidated balance sheets. Deferred tax assets and liabilities are recognized for the anticipated future tax effects of temporary differences between the financial statement basis and the tax basis of the Company's assets and liabilities using the applicable jurisdictional tax rates in effect the year the asset is realized or the liability is settled. The Company has not recognized any deferred tax liability, while the significant components of deferred tax assets are as follow: Year ended December 31, 2016 2017 Deferred tax assets Losses carried forward 10,110 12,176 Total deferred tax assets $ 10,110 $ 12,176 Less: valuation allowance (10,110 ) (12,176 ) Total deferred tax assets, net $ - $ - A valuation allowance for deferred tax assets is recorded when it is more likely than not that some or all of the benefit from the deferred tax asset will not be realized. The Company provides a valuation allowance to offset deferred tax assets for carry forward of operating losses incurred during the year in certain jurisdictions and for other deferred tax assets where, in the Company's opinion, it is more likely than not that the financial statement benefit of these losses will not be realized. The Company provides a valuation allowance for foreign tax loss carry forward to reflect the possible expiration of these benefits prior to their utilization. As of December 31, 2017, the valuation allowance for deferred tax assets amounted to $12,176. The earnings of certain of our subsidiaries are considered to be indefinitely reinvested. Should the Company make a distribution from these subsidiaries in the form of dividends or otherwise, the Company would be subject to additional income taxes. The unrecognized deferred tax liabilities related to these undistributed earnings was not practicable to be estimated as of December 31, 2017. Accordingly, the Company has not provided for taxes on these unremitted earnings. The Company is subject to taxation in various jurisdiction in which it conducts business. Tax years as early as 2010 remain subject to examination. As of December 31, 2017, the Company has various ongoing tax audits.

Earnings_ (loss) per share

Earnings/ (loss) per share	12 Months Ended
	Dec. 31, 2017
Earnings/ (loss) per share:
Earnings / (loss) per share	15. Earnings / (loss) per share: 2015 2016 2017 Income (numerator) Weighted- average number of outstanding shares (denominator) Amount per share Loss (numerator) Weighted- average number of outstanding share (denominator) Amount per share Loss (numerator) Weighted- average number of outstanding shares (denominator) Amount per share Class A Class A Class A Class A Class A Class A Class A Class B Class A Class B Class A Class B Basic net income/ (loss) per share: Net income/ (loss) $ 80,014 - - $ (3,241,518) - - $ (5,366 ) $ (36) - - - - Less: Non- vested common stock dividends declared and undistributed earnings (1,175 ) - - - - - - - - - - - Basic Earnings/ (loss) per share attributable to common stockholders $ 78,839 $ 15,082 5,227.36 $ (3,241,518) 10,538 (307,602.77) $ (5,366 ) $ (36) 25,070,978 167,314 (0.21) (0.21) Diluted net income/ (loss) per share: Allocation of undistributed earnings/ (losses) for basic computation - - - - - - (5,366 ) (36) - - - - Reallocation of undistributed earnings/ (losses) as a result of conversion of Class B to Class A shares - - - - - - - - - - - - Diluted Earnings/ (loss) per share $ 78,839 $ 15,082 5,227.36 $ (3,241,518) 10,538 (307,602.77) $ (5,366 ) $ (36 ) 25,070,978 167,314 (0.21) (0.21) Non-vested share-based payment awards that contain rights to receive non forfeitable dividends or dividend equivalents (whether paid or unpaid) and participate equally in undistributed earnings/ loss are participating securities and, thus, are included in the two-class method of computing earnings per share for the year ended December 31, 2015, 2016 and 2017. For the year ended December 31, 2015, non-vested participating restricted common shares were not included in the computation of diluted earnings/ loss per share because the effect is anti-dilutive. Earnings/loss per share of Class A and Class B common shares is computed using the two-class method. Basic earnings/loss per share is computed using the weighted average number of shares outstanding during the year ended December 31, 2017. Diluted net earnings/loss per share is computed using the weighted average number of shares and the effect of potentially dilutive securities outstanding during the year ended December 31, 2017. Potentially dilutive securities consist of restricted stock units and other contingently issuable shares. The computation of the diluted earnings/ loss per share of Class A common shares assumes the conversion of Class B common shares, while the diluted earnings/loss per share of Class B common shares does not assume the conversion of those shares. The Class B common shares are convertible into Class A common shares on a one-for-one basis, have equal voting rights and participate equally in dividend distributions and are not and will not be listed on a national securities exchange or a national market system (Note 11). As a result, the undistributed earnings/losses for the year ended December 31, 2017 are allocated based on the contractual participation rights of the Class A and Class B common shares on a proportionate basis. Furthermore, as we assume the conversion of Class B common shares in the computation of the diluted earnings/loss per share of Class A common shares, the undistributed earnings/losses are equal to net income/loss for that computation.

Geographic information for offs

Geographic information for offshore drilling operations	12 Months Ended
	Dec. 31, 2017
Geographic information for offshore drilling operations [Abstract]
Geographic information for offshore drilling operations	16. Geographic information for offshore drilling operations: The revenue shown in the table below is based upon the location where the drilling takes place: Country 2015 2016 2017 Angola 527,098 500,413 435,785 Brazil 581,438 517,885 333,186 Congo 157,235 241,953 185,040 Norway 231,189 74,925 53,509 Falklands 154,606 21,106 - Senegal 52,214 289,162 - Ivory Coast 33,723 1,164 - Other service revenues 10,697 7,059 - Total service revenues $ 1,748,200 1,653,667 1,007,520 The drilling units the Leiv Eiriksson, the Eirik Raude , the Ocean Rig Corcovado , the Ocean Rig Olympia , the Ocean Rig Poseidon , the Ocean Rig Mykonos, the Ocean Rig Mylos, the Ocean Rig Skyros , the Ocean Rig Athena , the Ocean Rig Apollo and the Ocean Rig Paros constitute the Company's long lived assets. For the year ended, December 31, 2016 and 2015, other service revenues relate to management fees from the services provided by the Company to the offshore drilling unit Cerrado .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies [Abstract]
Commitments and Contingencies	17. Commitments and Contingencies: 17.1 Legal proceedings: Various claims, suits, and complaints, including those involving government regulations and product liability, arise in the ordinary course of the offshore drilling business. As part of the Company's normal course of operations, the Company's customer may disagree on amounts due to the Company under the provision of the contracts which are normally settled through negotiations with the customer. Disputed amounts are normally reflected in revenues at such time as the Company reaches agreement with the customer on the amounts due. OCR Falklands Drilling Inc., a subsidiary of the Company, commenced arbitration proceedings against Premier Oil Plc. and Noble Energy Falklands Ltd. for terminating the contract on February 12, 2016, for the drilling unit Eirik Raude. Subsequently, the parties reached a commercial agreement to amicably settle this matter and a Settlement Agreement dated February 6, 2017, was entered into among the parties. HPOR Servicos De Consultaria Ltda ("HPOR") on September 1, 2016, commenced arbitration proceedings against, amongst others, the Company seeking payment of certain commissions that HPOR is alleging were due by, amongst others, the Company for certain agency and marketing services provided for the Ocean Rig Mykonos and the Ocean Rig Corcovado drilling units. The Company is disputing such allegations and has counterclaimed repayment of the commission already paid to HPOR. On March 7, 2018, the Tribunal issued awards in each of the references disallowing HPOR's claims and allowing the counterclaims brought by the Company, which we are currently evaluating. On March 7, 2016, two of the Company's subsidiaries commenced arbitration proceedings against Total E&P Angola for the termination of the contract with the drilling unit Ocean Rig Olympia . Subsequently, the parties reached a commercial agreement to amicably settle this matter and a Settlement Agreement dated December 29, 2017, was entered into among the parties. On December 22, 2016, Mayze Services Limited ("Mayze") issued a claim before the English High Court of Justice against the Company and others seeking payment of GBP 5,230,074 in respect of fees allegedly owed in connection with marketing services provided by Mayze to the Company. As of December 31, 2017, a provision of $4,000 has been recorded under "Legal settlements and other, net", in the accompanying consolidated statement of operations. On August 31, 2017, a complaint was filed in the High Court of the Republic of the Marshall Islands (Civil Action No. 2017-198) by certain of the Company's creditors against, among others, two subsidiaries of the Company, two of the Company's executive officers up to December 31, 2017– which currently are directors, the Company's manager TMS Offshore Services Ltd. and other parties. The plaintiffs purport to allege nine causes of action, including claims for avoidance and recovery of actual and/or constructive fraudulent conveyances under common law or 6 Del. Code §§ 1304(A)(1), 1305, 1307, and 1308; aiding and abetting fraudulent conveyances; and declaratory judgment under 30 MIRC § 202. All defendants moved to dismiss the case on October 31, 2017, and that motion has been briefed. In a scheduling conference held on February 14, 2018 in the Marshall Islands, the court scheduled oral argument to proceed on June 6, 2018. We are not in a position at this time to express an opinion as to the ultimate outcome of this matter, or to provide an estimate on the amount or range of any potential loss. On September 22, 2017, the Restructuring Effective Date, a shareholder filed an appeal of certain orders of the bankruptcy court to the United States District Court for the Southern District of New York. On the Restructuring Effective Date, we funded a preserved claims trust, or PCT. The PCT was established to preserve, for the benefit of Scheme Creditors, any causes of action held by the Company, Agon Shipping Inc. and/or Ocean Rig Investments Inc. arising from the facts and circumstances identified in the draft complaint prepared by certain of the Company’s creditors referenced above. If the trustees under the PCT determine that there is merit to any such claims, the trustees may take legal action for the benefit of all of the scheme creditors in the Restructuring. Except for the matters discussed above, the Company is not a party to any material litigation where claims or counterclaims have been filed against the Company other than routine legal proceedings incidental to its business. 17.2 Purchase Obligations: The following table sets forth the contractual purchase obligations of certain of the Company’s subsidiaries for the Ocean Rig Santorini and the Ocean Rig Crete , as of December 31, 2017, if they decide to go ahead with the construction of two drilling unit newbuildings. 2018 2019 Total Drilling units building contracts $ 417,931 520,165 $ 938,096 Total obligations $ 417,931 520,165 $ 938,096

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	18. Subsequent Events: 18.1 Effective January 1, 2018, the Company’s Board of Directors appointed Mr. Pankaj Khanna as President and Chief Executive Officer of the Company, Mr. Iraklis Sbarounis as Chief Financial Officer, Mr. David Cusiter as Chief Operations Officer and Mr. Anthony Kandylidis as Executive Vice Chairman of the Company. 18.2 During January 2018 and February 2018, we converted an aggregate of 349,711 Class B Common Shares, par value $0.01, into 349,711 Class A Common Shares, par value $0.01. Pursuant to our Company’s Second Amended and Restated Memorandum and Articles of Association each Class B Common Share is convertible into a Class A Common Share at a one for one conversion ratio. 18.3 On February 23, 2018, the Company signed a new drilling contract with Tullow Namibia Ltd., for a one-well drilling program plus options for drilling offshore West Africa. The contract is expected to commence in the third quarter of 2018 and to be performed by the Ocean Rig Poseidon. 18.4 On March 5, 2018, we held our 2018 Annual General Meeting of Shareholders.

Significant Accounting Polici26

Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2017
Significant Accounting policies [Abstract]
Principles of consolidation	(a) Principles of consolidation: The accompanying consolidated financial statements have been prepared in accordance with Generally Accepted Accounting Principles in the United States of America ("US GAAP") and include the accounts and operating results of Ocean Rig UDW, its wholly-owned subsidiaries and its VIEs. A VIE is an entity that in general does not have equity investors with substantive voting rights or that has equity investors that do not provide sufficient financial resources for the entity to support its activities. A controlling financial interest in a VIE is present when a company has the power to direct the activities of a VIE that most significantly impact the entity's economic performance and absorbs a majority of an entity's expected losses, receives a majority of an entity's expected residual returns, or both. All intercompany balances and transactions have been eliminated on consolidation. As of December 31, 2017 and 2016, the Company consolidated one VIE which supports our drilling operation in specific locations, for which it is deemed to be the primary beneficiary, i.e. it has a controlling financial interest in this entity. The VIE's total assets and liabilities, as of December 31, 2016, were $23,227 and $86,119, respectively, while total liabilities exceeded total assets by $62,892. The VIE's total assets and liabilities, as of December 31, 2017, were $15,029 and $92,622, respectively, while total liabilities exceeded total assets by $77,593. As of December 31, 2016 and December 31, 2017, the Company also consolidated one additional VIE due to the Trust (as defined) formed for the purpose of the amendment of the $462,000 Senior Secured Credit Facility (Note 9). Since the assets of the Trust can be used only to settle obligations of the Trust itself and at the same time creditors of the Trust do not have recourse to the general credit of the primary beneficiary, such assets and liabilities are analyzed as follows: December 31, 2016 December 31, 2017 ASSETS CURRENT ASSETS: Cash and cash equivalents $ 167 $ 110 Restricted cash 31,956 45,339 Trade accounts receivable, net 3,341 - Other current assets 1,884 1,929 Total current assets 37,348 47,378 FIXED ASSETS, NET: Drilling units, machinery and equipment, net 675,420 175,362 Total fixed assets, net 675,420 175,362 OTHER NON-CURRENT ASSETS: Restricted cash 20,008 - Total non-current assets, net 20,008 - Total assets $ 732,776 $ 222,740 LIABILITIES AND STOCKHOLDERS' EQUITY CURRENT LIABILITIES: Current portion of long-term debt, net of deferred financing costs $ 164,218 $ 81,632 Accounts payable and other current liabilities 5,218 249 Accrued liabilities 1,791 4,416 Total current liabilities 171,227 86,297 NON-CURRENT LIABILITIES Long term debt, net of current portion and deferred financing costs 82,947 - Total non-current liabilities 82,947 - COMMITMENTS AND CONTINGENCIES - - SHAREHOLDERS' EQUITY: Common stock, $20 par value; 1,000 shares authorized and issued at December 31, 2016 and 2017 20 20 Additional paid-in capital 960 960 Retained earnings 477,622 135,463 Total shareholders' equity 478,602 136,443 Total liabilities and shareholders' equity $ 732,776 $ 222,740
Use of estimates	(b) Use of estimates: The preparation of 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 consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Comprehensive income/ (loss)	(c) Comprehensive income/ (loss): The Company's comprehensive income/ (loss) is comprised of net income/ (loss), actuarial gains/ losses related to the adoption and implementation of Accounting Standard Codification ("ASC") 715, "Compensation-Retirement Benefits", as well as losses in the fair value of the derivatives that qualify for hedge accounting in accordance with ASC 815 "Derivatives and Hedging" and realized gains/losses on cash flow hedges associated with capitalized interest in accordance with ASC 815-30-35-38 "Derivatives and Hedging". During 2013, the Company adopted the requirements of Accounting Standard Update ("ASU") 2013-02, "Comprehensive Income (Topic 220) - Reporting of Amounts Reclassified out of Accumulated Other Comprehensive Income". The objective of this amendment is to improve the reporting of reclassifications out of accumulated other comprehensive income. The amendments do not change the current requirements for reporting net income or other comprehensive income in financial statements. However, the amendments require an entity to provide information about the amounts reclassified out of accumulated other comprehensive income by component. In addition, an entity is required to present, either on the face of the statement where net income is presented or in the notes, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income but only if the amount reclassified is required under US GAAP to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required under US GAAP to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures required under US GAAP that provide additional detail about those amounts.
Cash and Cash equivalents	(d) Cash and cash equivalents: The Company considers highly liquid investments such as time deposits and certificates of deposit with an original maturity of three months or less to be cash equivalents.
Restricted cash	(e) Restricted cash: Restricted cash may include (i) minimum liquidity collateral requirements or minimum required cash deposits, as defined in the Company's loan agreements; (ii) taxes withheld from employees and deposited in designated bank accounts; (iii) amounts pledged as collateral for bank guarantees to suppliers and, (iv) amounts pledged as collateral for credit facilities and swap agreements.
Trade accounts receivable net	(f) Trade accounts receivable net: The amount shown as accounts receivable, trade, at each balance sheet date, includes receivables from customers, net of an allowance for doubtful receivables. At each balance sheet date, all potentially uncollectible accounts are assessed individually for purposes of determining the appropriate allowance for doubtful receivables. As of December 31, 2016 and 2017, the provision for doubtful receivables was $22,368 and $13,526, respectively.
Concentration of credit risk	(g) Concentration of credit risk: Financial instruments, which potentially subject the Company to significant concentrations of credit risk, consist principally of cash and cash equivalents; trade accounts receivable and derivative contracts (interest rate swaps and foreign currency contracts). The maximum exposure to loss due to credit risk is the book value at the balance sheet date. The Company places its cash and cash equivalents, consisting mostly of bank deposits, with qualified financial institutions. The Company performs periodic evaluations of the relative credit standing of those financial institutions. The Company is exposed to credit risk in the event of non-performance by counter parties to derivative instruments; however, the Company limits its exposure by diversifying among counter parties. When considered necessary, additional arrangements are put in place to minimize credit risk, such as letters of credit or other forms of payment guarantees. The Company limits its credit risk with trade accounts receivable by performing ongoing credit evaluations of its customers' financial condition and generally does not require collateral for its trade accounts receivable . The Company has made advances for the construction of drilling units in a major shipyard in Korea. The ownership of the drilling units is transferred from the yard to the Company at delivery. As of December 31, 2017, cumulative installment payments made to the yard amounted to approximately $466,258 for the two drilling units under construction (Note 6). These installment payments are secured with irrevocable letters of guarantee, or "refund guarantees", issued by financial institutions.
Advances for drilling units under construction and related costs	(h) Advances for drilling units under construction and related costs: This represents amounts expended by the Company in accordance with the terms of the construction contracts for drilling units as well as other expenses incurred directly or under a management agreement with a related party in connection with onsite supervision. In addition, interest costs incurred during the construction (until the asset is substantially complete and ready for its intended use) are capitalized. The carrying value of drilling units under construction represents the accumulated costs at the balance sheet date. Cost components include payments for yard installments and variation orders, commissions to a related party, construction supervision, equipment, spare parts and capitalized interest.
Capitalized interest	(i) Capitalized interest: Interest expense is capitalized during the construction period of drilling units based on accumulated expenditures for the applicable project at the Company's current rate of borrowing. The amount of interest expense capitalized in an accounting period is determined by applying an interest rate (the "capitalization rate") to the average amount of accumulated expenditures for the asset during the period. The capitalization rates used in an accounting period are based on the rates applicable to borrowings outstanding during the period. The Company does not capitalize amounts in excess of actual interest expense incurred in the period. If the Company's financing plans associate a specific new borrowing with a qualifying asset, the Company uses the rate on that borrowing as the capitalization rate to be applied to that portion of the average accumulated expenditures for the asset that does not exceed the amount of that borrowing. If average accumulated expenditures for the asset exceed the amounts of specific new borrowings associated with the asset, the capitalization rate applied to such excess is a weighted average of the rates applicable to other borrowings of the Company. Capitalized interest expense for the years ended December 31 2015, 2016 and 2017, amounted to $26,055, $28,265 and $27,718, respectively (Note 13).
Insurance claims	(j) Insurance claims: The Company records insurance claim recoveries for insured losses incurred on damages to fixed assets, loss of hire and for insured crew medical expenses under "Other current assets". Insurance claims are recorded, net of any deductible amounts, at the time the Company's fixed assets suffer insured damages or loss due to the drilling unit being wholly or partially deprived of income as a consequence of damage to the unit or when crew medical expenses are incurred, recovery is probable under the related insurance policies and the Company can make an estimate of the amount to be reimbursed following the insurance claim.
Foreign currency translation	(k) Foreign currency translation: The functional currency of the Company is the U.S. Dollar since the Company operates in international drilling markets and therefore, primarily transacts business in U.S. Dollars. The Company's accounting records are maintained in U.S. Dollars. Transactions involving other currencies during the year are converted into U.S. Dollars using the exchange rates in effect at the time of the transactions. At the balance sheet dates, monetary assets and liabilities, which are denominated in other currencies, are translated into U.S. Dollars at the year-end exchange rates. Resulting gains or losses are included in "Other, net" in the accompanying consolidated statements of operations.
Long lived assets held for sale	(l) Long lived assets held for sale: The Company classifies long lived assets and disposal groups as being held for sale in accordance with ASC 360, "Property, Plant and Equipment", when: (i) management has committed to a plan to sell the long lived assets; (ii) the long lived assets are available for immediate sale in their present condition; (iii) an active program to locate a buyer and other actions required to complete the plan to sell the long lived assets have been initiated; (iv) the sale of the long lived assets is probable and transfer of the asset is expected to qualify for recognition as a completed sale within one year; and (v) the long lived assets are being actively marketed for sale at a price that is reasonable in relation to its current fair value and (vi) actions required to complete the plan indicate that it is unlikely that significant changes to the plan will be made or that the plan will be withdrawn. Long lived assets classified as held for sale are measured at the lower of their carrying amount or fair value less cost to sell. These long lived assets are not depreciated once they meet the criteria to be classified as held for sale. If circumstances arise that previously were considered unlikely and, as a result, the Company decides not to sell a long-lived asset previously classified as held for sale, the asset shall be reclassified as held and used. A long-lived asset that is reclassified shall be measured individually at the lower of its carrying amount before the asset or disposal group was classified as held for sale, adjusted for any depreciation expense that would have been recognized had the asset or disposal group been continuously classified as held and used and its fair value at the date of the subsequent decision not to sell.
Drilling units, machinery and equipment, net	(m) Drilling units, machinery and equipment, net: Drilling units are stated at historical cost less accumulated depreciation. Such costs include the cost of adding or replacing parts of drilling unit machinery and equipment when the cost is incurred, if the recognition criteria are met. The recognition criteria require that the cost incurred extends the useful life of a drilling unit. The carrying amounts of those parts that are replaced are written off and the cost of the new parts is capitalized. Depreciation is calculated on a straight- line basis over the useful life of the assets after considering the estimated residual value as follows: bare deck 30 years and other asset parts from five to 30 years for the drilling units. Effective January 1, 2017, the Company revised its' residual value estimate for each drilling unit. The Company assessed this residual value based on current and historical market trends. The effect of this change in accounting estimate, which did not require retrospective adoption as per ASC 250 "Accounting Changes and Error Corrections," was to increase net loss for the year ended December 31, 2017 by $14,469 and had also an increase on loss per common share, basic and diluted by $(0.57).
Impairment of long-lived assets	(n) Impairment of long-lived assets: The Company reviews for impairment long-lived assets whenever events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. To the extent impairment indicators are present; the Company assesses recoverability of the carrying value of the asset by estimating the undiscounted future net cash flows expected to result from the asset. In developing estimates of future undiscounted cash flows, the Company makes assumptions and estimates about the drilling units future performance, with the significant assumptions being related to drilling rates, fleet utilization, operating expenses, capital expenditures, class survey costs, residual value and the estimated remaining useful life of each drilling unit. The projected net operating cash flows are determined by considering the drilling revenues from existing drilling contracts for the fixed days, while for the unfixed days the Company uses an estimated daily rate equivalent by utilizing available market data. The salvage value used in the impairment test is estimated using the Light Weight Tons (LWT) and the market scrap rate. The remaining significant assumptions used to develop estimates of future undiscounted cash flows are based on historical trends as well as future expectations. Although the Company believes that the assumptions used to evaluate potential impairment are reasonable and appropriate, such assumptions are highly subjective. If the Company's estimate of undiscounted future cash flows for any drilling unit is lower than the carrying value, the carrying value is written down, by recording a charge to operations, to the drilling units' fair market value if the fair market value is lower than the drilling unit's carrying value. The fair market value for the drilling unit is obtained by independent appraisals. For the year ended December 31, 2015, 2016 and 2017, as a result of the impairment review, the Company determined that the carrying amount of two, eight and one units, respectively, was not recoverable and, therefore, a charge of $414,986, $3,658,815 and $473,343, respectively, was recognized and is included in "Impairment loss", in the accompanying consolidated statement of operations (Note 7). In addition, an impairment charge of total advances and related costs provided to the yard, amounting to $92.4 million for the drilling unit under construction Ocean Rig Amorgos (Note 6) and the impairment of $25.2 million relating to the cashflow hedges for interest capitalized on drilling units impaired (Note 10) is included in "Impairment loss" in the consolidated statement of operations. For the year ended December 31, 2017 the Company determined that the full amount of the carrying value of the two drilling units under construction Ocean Rig Crete and Ocean Rig Santorini was not recoverable and, therefore, an impairment charge of $573,162 was recognized and included in the "Impairment loss" in the consolidated statement of operations (Note 6) and a loss of $2,323 due to the reclassification of two drilling units as held and used (previously classified as held for sale) (Note 10 and Note 7) was recognized and included in "Impairment loss", in the consolidated statement of operations.
Reorganizations	(o) Reorganizations: In accordance with GAAP, the Company has applied ASC 852 "Reorganizations" (ASC 852), in preparing the accompanying consolidated financial statements. ASC 852 requires that the financial statements, for periods subsequent to the Chapter 15 filing, distinguish transactions and events that are directly associated with the reorganization from the ongoing operations of the business. Accordingly, certain revenues, expenses (including professional fees), realized gains and losses and provisions for losses that are realized or incurred in the Chapter 15 proceedings are recorded in reorganization gain, net on the accompanying consolidated statement of operations. Upon emerging from Chapter 15 proceedings on September 22, 2017, the Company did not meet the criteria to qualify for fresh-start reporting. Therefore, the discharge of debt is reported as an extinguishment of debt and classified in accordance with Subtopic 225-20. Non-monetary transactions - exchange of the capital stock of an entity for nonmonetary assets or services : Such transactions are measured at the fair value of the consideration received or the fair value of the equity instruments issued, whichever is more reliably measurable. Any difference between the fair value and the transaction price is considered as gain or loss for the Company. The Company considered as appropriate date to use to measure the fair value of the equity instruments issued, the restructuring effective date and accounts for such transactions in accordance with ASC 845 at fair value of its common shares on that date.
Class costs	(p) Class costs: The Company follows the direct expense method of accounting for periodic class costs incurred during special surveys of drilling units, normally every five years. Class costs and other maintenance costs are expensed in the period incurred and included in "Drilling units operating expenses."
Deferred financing costs	(q) Deferred financing costs: Deferred financing costs include fees, commissions and legal expenses associated with the Company's long- term debt. These costs are amortized over the life of the related debt using the effective interest method and are included in interest expense. Unamortized fees relating to loans repaid or refinanced as debt extinguishments are expensed as interest and finance costs in the period the repayment or extinguishment is made. Arrangement fees paid to lenders for loans which the Company has not drawn down are capitalized and included in other current and non-current assets. Amortization and write offs for each of the years ended December 31 2015, 2016 and 2017, amounted to $24,033, $21,040 and $61,212, respectively (Note 13).
Revenue and related expenses	(r) Revenue and related expenses: Revenues: The Company's services and deliverables are generally sold based upon contracts with customers that include fixed or determinable prices. The Company recognizes revenue when delivery occurs, as directed by its customer, and collectability is reasonably assured. The Company evaluates if there are multiple deliverables within its contracts and whether the agreement conveys the right to use the drilling units for a stated period of time and meets the criteria for lease accounting, in addition to providing a drilling services element, which is generally compensated for by day rates. In connection with drilling contracts, the Company may also receive revenues for preparation and mobilization of equipment and personnel or for capital improvements to the drilling units and day rate or fixed price mobilization and demobilization fees. Revenues are recorded net of agents' commissions. There are two types of drilling contracts: well contracts and term contracts. (i) Well contracts: Well contracts are contracts under which the assignment is to drill a certain number of wells. Revenue from day-rate based compensation for drilling operations is recognized in the period during which the services are rendered at the rates established in the contracts. All mobilization revenues, direct incremental expenses of mobilization and contributions from customers for capital improvements are initially deferred and recognized as revenues and expenses, as applicable, over the estimated duration of the drilling period. To the extent that expenses exceed revenue to be recognized, they are expensed as incurred. Demobilization revenues and expenses are recognized over the demobilization period. All revenues for well contracts are recognized as "Service revenues" in the consolidated statement of operations. (ii) Term contracts: Term contracts are contracts under which the assignment is to operate the unit for a specified period of time. For these types of contracts the Company determines whether the arrangement is a multiple element arrangement containing both a lease element and drilling services element. For revenues derived from contracts that contain a lease, the lease elements are recognized as "Leasing revenues" in the consolidated statement of operations on a basis approximating straight line over the lease period. The drilling services element is recognized as "Service revenues" in the period in which the services are rendered at estimated fair value. Revenues related to the drilling element of mobilization and direct incremental expenses of drilling services are deferred and recognized over the estimated duration of the drilling period. To the extent that expenses exceed revenue to be recognized, they are expensed as incurred. Demobilization fees and expenses are recognized over the demobilization period. Contributions from customers for capital improvements are initially deferred and recognized as revenues over the estimated duration of the drilling contract. Other revenues: Other revenues represent the revenues derived from customer contract terminations. The Company recognizes revenues from contract terminations as it has fulfilled obligations for such terminations and when all contingencies have expired . Reimbursable revenues: Effective January 1, 2017, reimbursements received from the customers for the provision of catering services in accordance with relevant contracts are recorded as revenue. The related costs are recorded as running expenses in the same period.
Earnings / (loss) per common share	(s) Earnings / (loss) per common share: Basic earnings / (loss) per common share are computed by dividing net income/ (loss) available to common stockholders by the weighted average number of common shares outstanding during the year. Diluted earnings per common share reflect the potential dilution that could occur if securities or other contracts to issue common shares were exercised. Dilution has been computed by the treasury stock method whereby all of the Company's dilutive securities are assumed to be exercised or converted and the proceeds used to repurchase common shares at the weighted average market price of the Company's common shares during the relevant periods. The incremental shares (the difference between the number of shares assumed issued and the number of shares assumed purchased) are included in the denominator of the diluted earnings / (loss) per share computation.
Segment reporting	(t) Segment reporting: The Company has determined that it operates in one reportable segment, the offshore drilling operations.
Financial instruments	(u) Financial instruments : The Company designates its derivatives based upon guidance of ASC 815, "Derivatives and Hedging" which establishes accounting and reporting requirements for derivative instruments, including certain derivative instruments embedded in other contracts and for hedging activities. The guidance on accounting for certain derivative instruments and certain hedging activities requires all derivative instruments to be recorded on the balance sheet as either an asset or liability measured at its fair value, with changes in fair value recognized in earnings unless specific hedge accounting criteria are met. As of December 31, 2017 the Company has adopted the provisions of ASU 2016-06 on the Contingent Put and Call Options in Debt Instruments and provided relevant disclosures in Note 9. By this change there is no cumulative effect on the Accumulated Deficit, as of the beginning of the earliest period presented. (i) Hedge accounting: At the inception of a hedge relationship, the Company formally designates and documents the hedge relationship to which the Company wishes to apply hedge accounting and the risk management objective and strategy undertaken for the hedge. The documentation includes identification of the hedging instrument, hedged item or transaction, the nature of the risk being hedged and how the entity will assess the hedging instrument's effectiveness in offsetting exposure to changes in the hedged item's cash flows attributable to the hedged risk. Such hedges are expected to be highly effective in achieving offsetting changes in cash flows and are assessed on an ongoing basis to determine whether they actually have been highly effective throughout the financial reporting periods for which they were designated. The Company is party to interest swap agreements where it receives a floating interest rate and pays a fixed interest rate for a certain period. Contracts which meet the strict criteria for hedge accounting are accounted for as cash flow hedges. A cash flow hedge is a hedge of the exposure to variability in cash flows that is attributable to a particular risk associated with a recognized asset or liability, or a highly probable forecasted transaction that could affect profit or loss. The effective portion of the gain or loss on the hedging instrument is recognized directly as a component of "Accumulated other comprehensive income/ (loss)" in equity, while any ineffective portion, if any, is recognized immediately in current period earnings. The Company discontinues cash flow hedge accounting if the hedging instrument expires and it no longer meets the criteria for hedge accounting or designation is revoked by the Company. At that time, any cumulative gain or loss on the hedging instrument recognized in equity is kept in equity until the forecasted transaction occurs. When the forecasted transaction occurs, any cumulative gain or loss on the hedging instrument is recognized in the consolidated statement of operations. If a hedged transaction is no longer expected to occur, the net cumulative gain or loss recognized in equity is transferred to net profit or loss for the year as financial income or expense. (ii) Other derivatives: Changes in the fair value of derivative instruments that have not been designated as hedging instruments are reported in current period earnings.
Fair value measurements	(v) Fair value measurements: The Company follows the provisions of ASC 820, "Fair Value Measurements and Disclosures" which defines and provides guidance as to the measurement of fair value. ASC 820 creates a hierarchy of measurement and indicates that, when possible, fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. The fair value hierarchy gives the highest priority (Level 1) to quoted prices in active markets and the lowest priority (Level 3) to unobservable data, for example, the reporting entities own data. Under the standard, fair value measurements are separately disclosed by level within the fair value hierarchy (Note 10).
Income taxes	(w) Income taxes: Income taxes have been provided for based upon the tax laws and rates in effect in the countries in which the Company's operations are conducted and income is earned. There is no expected relationship between the provision for/or benefit from income taxes and income or loss before income taxes because the countries in which the Company operates have taxation regimes that vary not only with respect to the nominal rate, but also in terms of the availability of deductions, credits and other benefits. Variations also arise because income earned and taxed in any particular country or countries may fluctuate from year to year. Deferred tax assets and liabilities are recognized for the anticipated future tax effects of temporary differences between the financial statement basis and the tax basis of the Company's assets and liabilities using the applicable jurisdictional tax rates in effect at the year in which the asset is realized or the liability settled. A valuation allowance for deferred tax assets is recorded when it is more likely than not that some or all of the benefit from the deferred tax asset will not be realized. As of December 31, 2017 the Company has adopted the provisions of ASU 2015-17 on the Balance Sheet Classification on Deferred Taxes , which requires all deferred tax assets and liabilities, along with any related valuation allowance, be classified as noncurrent on the balance sheet. The new guidance did not impact the consolidated financial statements. The Company accrues interest and penalties related to its liabilities for unrecognized tax benefits as a component of income tax expense.
Commitments and contingencies	(x) Commitments and contingencies: Provisions are recognized when: the Company has a present legal or constructive obligation as a result of past events; it is probable that an outflow of resources embodying economic benefits will be required to settle the obligation; and a reliable estimate of the amount of the obligation can be made. Provisions are reviewed at each balance sheet date.
Stock-based compensation	(y) Stock-based compensation: Stock-based compensation represents vested and non-vested common shares granted to certain employees for their services. The Company calculates total compensation expense for the award based on its fair value on the grant date and amortizes the total compensation on an accelerated basis over the vesting period of the award or service period and recognizes forfeitures as they occur (Note 11). As of December 31, 2017, the Company has adopted the provisions of ASU 2016-09, which did not impact the consolidated financial statements.
Inventories	(z) Inventories: Inventories consist of short term operating supplies held in warehouses which are stated at their historical cost, and consumable bunkers (if any), whose cost is determined by the first in - first out method. Inventories are recorded under "Other Current Assets". In July 2015, the FASB issued ASU No. 2015-11 – Inventory, as part of FASB Simplification Initiative, according to which the entities are required to measure inventory at the lower of cost or net realizable value. Net realizable value is defined as estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. This update was effective for public entities for fiscal years beginning after December 15, 2016, including interim periods within those fiscal years prospectively. During fiscal year 2017, the Company adopted the aforementioned update, which did not impact its results of operations, financial position or cash flows, in the current and previous interim and annual reporting periods.
Consolidation	(aa) Consolidation: In February 2015, the FASB issued Accounting Standards Update No. 2015-02 (ASU 2015-02): Consolidation - Amendments to the Consolidation Analysis, which changes the guidance as to whether an entity is a variable interest entity (VIE) or a voting interest entity and how related parties are considered in the VIE model. As of December 31, 2016, the Company has adopted the provisions of ASU 2015-02, which did not impact the consolidated financial statements.
Going Concern	(aa) Going Concern: In August 2014, the FASB issued ASU No. 2014-15–Presentation of Financial Statements - Going Concern. ASU 2014-15 provides guidance about management's responsibility to evaluate whether there is substantial doubt about an entity's ability to continue as a going concern and to provide related footnote disclosures. ASU 2014-15 requires an entity's management to evaluate at each reporting period based on the relevant conditions and events that are known at the date of financial statements are issued, whether there are conditions or events, that raise substantial doubt about the entity's ability to continue as a going concern within one year after the date that the financial statements are issued and to disclose the necessary information. ASU 2014-15 is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. Effective January 1, 2017, the Company has adopted the provisions of ASU 2014-15 and provided the required note disclosure (Note 3).
Recent accounting pronouncements	(ab) Recent accounting pronouncements: Accounting Changes and Error Corrections: In January 2017, FASB issued ASU 2017-03, "Accounting Changes and Error Corrections (Topic 250) and Investments-Equity Method and Joint Ventures (Topic 323)". The ASU amends the Codification for SEC staff announcements made at recent Emerging Issues Task Force (EITF) meetings. The SEC guidance that specifically relates to our combined financial statement was from the September 2016 meeting, where the SEC staff expressed their expectations about the extent of disclosures registrants should make about the effects of the new FASB guidance as well as any amendments issued prior to adoption, on revenue (ASU 2014-09), leases (ASU 2016-02) and credit losses on financial instruments (ASU 2016-13) in accordance with SAB Topic 11.M. Registrants are required to disclose the effect that recently issued accounting standards will have on their financial statements when adopted in a future period. In cases where a registrant cannot reasonably estimate the impact of the adoption, then additional qualitative disclosures should be considered. The ASU incorporates these SEC staff views into ASC 250 and adds references to that guidance in the transition paragraphs of each of the three new standards. Leases: In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842), which requires lessees to recognize most leases on the balance sheet. This is expected to increase both reported assets and liabilities. The new lease standard does not substantially change lessor accounting. The accounting standards update requires (a) lessees to recognize a right to use asset and a lease liability for virtually all leases, and (b) updates previous accounting standards for lessors to align certain requirements with the updates to lessee accounting standards and the revenue recognition accounting standards. The update is effective for interim and annual periods beginning after December 15, 2018, including interim periods within those annual periods. The Company previously disclosed its intention to adopt this standard at the same time as it adopted the new revenue standard discussed below; however, the Company now expects to adopt this new guidance in the first quarter of 2019. The Company is currently evaluating the impact that this new guidance will have on its consolidated financial statements. Revenue from Contracts with Customers: In March 2016, the FASB issued ASU 2016-08, "Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU 2016-08"), which clarifies the implementation guidance on principal versus agent considerations. In May and April 2016, the FASB issued two Updates with respect to Topic 606: ASU 2016-10, "Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing" and ASU 2016-12, "Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients." The amendments in these Updates do not change the core principle of the guidance in Topic 606, which is that an entity should 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 by applying the following steps: (1) Identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. The amendments in Update 2016-10 simply clarify the following two aspects of Topic 606: (1) identifying performance obligations and (2) licensing implementation guidance. The amendments in Update 2016-12 similarly affect only certain narrow aspects of Topic 606; namely, (1) "Assessing the Collectibility Criterion in Paragraph 606-10-25-1(e) and Accounting for Contracts That Do Not Meet the Criteria for Step 1 (Applying Paragraph 606-10-25-7)," (2) "Presentation of Sales Taxes and Other Similar Taxes Collected from Customers," (3) "Noncash Consideration," (4) "Contract Modifications at Transition," (5) "Completed Contracts at Transition," and (6) "Technical Correction." The amendments in these Updates also affect the guidance in Accounting Standards Update 2014-09, Revenue from Contracts with Customers (Topic 606), which is not yet effective. The effective date and transition requirements for the amendments in these Updates are the same as the effective date and transition requirements in Topic 606 (and any other Topic amended by Update 2014-09). Accounting Standards Update 2015-14, "Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date," has deferred the effective date of Update 2014-09 for public business entities to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Earlier application is permitted. The new revenue standard may be applied using either of the following transition methods: (1) a full retrospective approach reflecting the application of the standard in each prior reporting period with the option to elect certain practical expedients, or (2) a modified retrospective approach with the cumulative effect of initially adopting the standard recognized at the date of adoption (which includes additional footnote disclosures). On January 1, 2018, the Company adopted the accounting standards update that 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, using the modified retrospective method. The effect on Company's consolidated financial statements due to the adoption of the new accounting standard is based on the evaluation of the contract ‑ specific facts and circumstances and has no material effect on the consolidated balance sheets, statements of operations and cash flows. The company is currently evaluating the requirements and assessing the impact such requirements may have on the disclosures contained in the notes to consolidated financial statements. Statement of Cash Flows: In August 2016, the FASB issued ASU No. 2016-15- Statement of Cash Flows (Topic 230) – Classification of Certain Cash Receipts and Cash Payments which addresses certain cash flow issues with the objective of reducing the existing diversity in practice: ASU 2016-15 is effective for fiscal years beginning after December 15, 2017, including interim periods within that reporting period, however, early adoption is permitted. The Company is currently evaluating the provisions of this guidance and assessing its impact on its consolidated financial statements and notes disclosures. In November 2016, the FASB issued ASU No. 2016-18—Statement of Cash Flows (Topic 230) - Restricted Cash which addresses the requirement that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The amendments in this Update apply to all entities that have restricted cash or restricted cash equivalents and are required to present a statement of cash flows under Topic 230. ASU 2016-18 is effective for fiscal years beginning after December 15, 2017, including interim periods within that reporting period, however early adoption is permitted. The Company is currently evaluating the provisions of this guidance and assessing its impact on its consolidated financial statements and notes disclosures. Measurement of Credit Losses on Financial Instruments: On June 16, 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326), which introduces a new model for recognizing credit losses on financial instruments based on an estimate of current expected credit losses. The new model will apply to: (1) loans, accounts receivable, trade receivables, and other financial assets measured at amortized cost, (2) loan commitments and certain other off-balance sheet credit exposures, (3) debt securities and other financial assets measured at fair value through other comprehensive income, and (4) beneficial interests in securitized financial assets. This update is effective for annual and interim periods beginning after January 1, 2020. The Company is currently evaluating the provisions of this guidance and assessing its impact on its consolidated financial statements and notes disclosures. Tax Accounting for Intra-Entity Asset Transfers: On October 24, 2016, the FASB issued ASU 2016-16, Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory, which requires entities to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transaction occurs as opposed to deferring tax consequences and amortizing them into future periods. This update is effective for annual and interim periods, beginning after January 1, 2018, with early adoption permitted and requires a modified retrospective approach with a cumulative-effect adjustment directly to retained earnings at the beginning of the period of adoption. The Company is currently evaluating the provisions of this guidance and assessing its impact on its consolidated financial statements and notes disclosures. Definition of business: In January 2017, the FASB issued ASU 2017-01 Business Combinations to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisition (or disposals) of assets of business. Under current implementation guidance, the existence of an integrated set of acquired activities (inputs and processes that generate outputs) constitutes an acquisition of business. This ASU provides a screen to determine when a set of assets and activities does not constitute a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set in not a business. This update is effective for public entities with reporting periods beginning after December 15, 2017, including interim periods within those years. The amendments of this ASU should be applied prospectively on or after the effective date. Early adoption is permitted, including adoption in an interim period 1) for transactions for which the acquisition date occurs before the issuance date or effective date of the ASU, only when the transaction has not been reported in financial statements that have been issued or made available for issuance and 2) for transactions in which a subsidiary is deconsolidated or a group of assets is derecognized that occurs before the issuance date or effective date of the amendments, only when the transaction has not been reported in financial statements that have been issued or made available for issuance. This FASB standard Update is not expected to have a material effect on the Company's future or historical statements of cash flows; however, Management will assess such impact, if circumstances arise.

Basis of Presentation and Gen27

Basis of Presentation and General Infomation (Tables)	12 Months Ended
	Dec. 31, 2017
Basis of Presentation and General Information [Abstract]
Schedule of revenue by major charterer	Year ended December 31, 2015 2016 2017 Customer A 14 % 11 % - Customer B 19 % 20 % 33% Customer C 13 % - - Customer D 15 % 31 % 40% Customer E 13 % 14 % - Customer F 15 % 18 % -

Significant Accounting Polici28

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Drillship Alonissos Stock Trust
Balance Sheet of Variable Interest Entity	December 31, 2016 December 31, 2017 ASSETS CURRENT ASSETS: Cash and cash equivalents $ 167 $ 110 Restricted cash 31,956 45,339 Trade accounts receivable, net 3,341 - Other current assets 1,884 1,929 Total current assets 37,348 47,378 FIXED ASSETS, NET: Drilling units, machinery and equipment, net 675,420 175,362 Total fixed assets, net 675,420 175,362 OTHER NON-CURRENT ASSETS: Restricted cash 20,008 - Total non-current assets, net 20,008 - Total assets $ 732,776 $ 222,740 LIABILITIES AND STOCKHOLDERS' EQUITY CURRENT LIABILITIES: Current portion of long-term debt, net of deferred financing costs $ 164,218 $ 81,632 Accounts payable and other current liabilities 5,218 249 Accrued liabilities 1,791 4,416 Total current liabilities 171,227 86,297 NON-CURRENT LIABILITIES Long term debt, net of current portion and deferred financing costs 82,947 - Total non-current liabilities 82,947 - COMMITMENTS AND CONTINGENCIES - - SHAREHOLDERS' EQUITY: Common stock, $20 par value; 1,000 shares authorized and issued at December 31, 2016 and 2017 20 20 Additional paid-in capital 960 960 Retained earnings 477,622 135,463 Total shareholders' equity 478,602 136,443 Total liabilities and shareholders' equity $ 732,776 $ 222,740

Transactions with Related Par29

Transactions with Related Parties (Tables)	12 Months Ended
	Dec. 31, 2017
Transactions with Related Parties [Abstract]
Schedule of related party transactions	Year ended December 31, 2016 2017 Balance Sheet Advances for drilling units under construction and related costs $ 1,569 $ - Drilling units, machinery and equipment, net 488 - Due to related parties $ (7,231 ) $ (726 ) Accrued liabilities $ (3,100 ) $ (11,786 ) Year ended December 31, Statement of Operations 2015 2016 2017 Revenues – commission fees $ 16,524 $ 14,925 $ 10,342 Drilling units operating expenses $ - $ 4,209 $ 904 Amortization and write-off of financing fees $ 2,781 $ - $ - General and administrative expenses $ 7,409 $ 24,924 $ 26,008 Interest income $ 6,024 $ - $ - Reorganization expenses (including non-cash issuance of shares and other expenses) $ - $ - $ 223,178

Other Current Assets (Tables)

Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Other Current Assets [Abstract]
Other Current Assets	December 31, 2016 2017 Inventories $ 12,988 $ 9,573 Deferred mobilization expenses 6,351 6,482 Prepayments and advances 10,500 17,064 Intangible assets, net - 402 Insurance claims - 2,980 Other 85 1,485 Total $ 29,924 $ 37,986

Advances for drilling units u31

Advances for drilling units under construction and related costs (Tables)	12 Months Ended
	Dec. 31, 2017
Advances For Drilling Unit Under Construction And Related Costs [Abstract]
Advances for drilling unit under construction and related costs	December 31, 2016 2017 Balance at beginning of year $ 394,852 $ 545,469 Advances for drilling units under construction and related costs 242,988 27,693 Impairment loss (advances and related costs for drilling unit under construction) (92,371 ) (573,162) Balance at end of year $ 545,469 $ -

Drilling units, machinery and32

Drilling units, machinery and equipment, net (Tables)	12 Months Ended
	Dec. 31, 2017
Drilling Units, Machinery And Equipment, Net [Abstract]
Drilling units, machinery and equipment, net	Cost Accumulated Depreciation Net Book Value Balance December 31, 2015 $ 7,258,995 $ (922,103 ) $ 6,336,892 Additions 99,515 - 99,515 Disposal of assets (7,756 ) 133 (7,623 ) Impairment loss (3,658,815 ) - (3,658,815 ) Depreciation - (331,677 ) (331,677 ) Balance December 31, 2016 $ 3,691,939 (1,253,647 ) 2,438,292 Additions 9,726 - 9,726 Disposal of assets (1,648 ) 1,212 (436 ) Impairment loss (475,666 ) - (475,666 ) Depreciation - (119,749 ) (119,749 ) Balance December 31, 2017 $ 3,224,351 (1,372,184 ) 1,852,167

Other non-current assets (Table

Other non-current assets (Tables)	12 Months Ended
	Dec. 31, 2017
Other non-current assets [Abstract]
Other non-current assets	December 31, 2016 2017 Deferred mobilization expenses $ 5,564 $ 4,080 Intangible assets, net 1,845 - Prepaid investments 425 - Security deposit - 5,000 Total $ 7,834 $ 9,080

Long-term Debt (Tables)

Long-term Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Long-term Debt [Abstract]
Long-term debt	December 31, 2016 December 31, 2017 $1.3 billion Senior Secured Term Loan B Facility $ 1,270,750 $ - $1.9 billion Secured Term Loan B Facility 1,838,250 - $462 million Senior Secured Credit Facility 249,542 81,886 $500 million Senior Unsecured Notes 130,974 - $800 million Senior Secured Notes 459,723 - $450 million Senior Secured Term Loan Facility - 450,000 Less: Deferred financing costs (61,466 ) (254) Total debt 3,887,773 531,632 Less: Current portion (640,557 ) (81,632 ) Long-term portion $ 3,247,216 $ 450,000
Loan movements for Company's debt	Loan Loan Agreement Date Original Amount December 31, 2016 New Loan Discharges/ Repayment December 31, 2017 $800 million Senior Notes September 20, 2012 $ 800,000 459,723 - (459,723 ) $ - $1.9 billion Secured Term Loan B Facility July 12, 2013 1,900,000 1,838,250 - (1,838,250 ) - $500 million Senior Unsecured Notes March 26, 2014 500,000 130,974 - (130,974 ) - $1.3 billion Senior Secured Term Loan B July 25, 2014 1,300,000 1,270,750 - (1,270,750 ) - $462 million Senior Secured Credit Facility February 13, 2015 462,000 249,542 - (167,656 ) 81,886 $ 450 million Senior Secured Term Loan Facility September 22, 2017 450,000 - 450,000 - 450,000 $ 3,949,239 $ 450,000 $ (3,867,353 ) $ 531,886
Annual principal payments	2018 $ 81,886 2019 - 2020 - 2021 - 2022 - 2023 and thereafter 450,000 Total principal payments 531,886 Less: Financing fees (254 ) Total debt $ 531,632

Financial Instruments and Fai35

Financial Instruments and Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Financial Instruments and Fair Value Measurements [Abstract]
Fair Values of Derivative Instruments in the Statement of Financial Position and Statement of Operations	Amount of Loss Derivatives not designated as hedging instruments Location of Loss Recognized Year ended December 31, 2015 Year ended December 31, 2016 Year ended December 31, 2017 Interest rate swaps Loss on interest rate swaps $ (11,513 ) $ (4,388 ) $ -
Recurring measurements	The following table summarizes the valuation of assets measured at fair value on a non-recurring basis as of December 31, 2016. Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Impairment loss Non-Recurring measurements: Long-lived assets $ - $ 1,035,499 $ - $ (3,658,815 ) The following table summarizes the valuation of assets measured at fair value on a non-recurring basis as of December 31, 2017. Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Impairment loss Non-Recurring measurements: Long-lived assets $ - $ 234,139 $ - $ (475,666 )

Common Stock and Additional P36

Common Stock and Additional Paid-in Capital (Tables)	12 Months Ended
	Dec. 31, 2017
Common Stock and Additional Paid-in Capital [Abstract]
Common Stock and Additional Paid-in Capital	Number of non vested shares Weighted average grant date fair value per non vested shares Balance December 31, 2015 44 $ 99,360.00 Forfeited (17 ) 92,736.00 Vested (16 ) 114,356.00 Balance December 31, 2016 11 $ 87,032.00 Granted 12,000 25.56 Vested (12,011) 105.24 Balance December 31, 2017 - $ - Number of vested shares Weighted average grant date fair value per vested shares As at December 31, 2015 66 $ 139,380.00 Vested shares granted in prior years 16 114,356.00 Granted and vested shares in prior years, but cancelled during 2016 (45 ) 124,384.00 As at December 31, 2016 37 $ 146,648.00 Vested shares granted in prior years 11 87,032.00 Vested shares granted in 2017 12,000 25.56 As at December 31, 2017 12,048 $ 558.94

Accumulated Other Comprehensi37

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract]
Accumulated Other Comprehensive Income / (Loss)	December 31, 2016 2017 Actuarial pension gain 3,346 3,476 Total $ 3,346 $ 3,476

Interest and Finance Costs (Tab

Interest and Finance Costs (Tables)	12 Months Ended
	Dec. 31, 2017
Interest and Finance Costs [Abstract]
Interest And Finance Costs	December 31, 2015 2016 2017 Interest costs on long term debt $ 276,510 $ 235,182 $ 214,282 Amortization and write off of financing fees 24,033 21,040 61,212 Discount on receivable from drilling contract 3,018 (2,821) (308 ) Capitalized borrowing costs (26,055 ) (28,265 ) (27,718 ) Commissions, commitment fees and other financial expenses 2,842 1,845 874 Total $ 280,348 $ 226,981 $ 248,342

Income Tax (Tables)

Income Tax (Tables)	12 Months Ended
	Dec. 31, 2017
Income Taxes [Abstract]
Schedule of income before income tax, domestic and foreign	Year ended December 31 2015 2016 2017 Domestic income/ (loss) (Marshall Islands/ Cayman Islands) $ 219,900 $ 126,244 $ - Foreign income 185,742 93,633 - Domestic (loss)/ income (Cayman Islands) - (97,939) (276,471 ) Foreign income - 394,196 558,005 Total income before taxes, excluding impairment loss, gain from repurchases of senior notes, reorganization gain, net and loss from issuance of shares upon restructuring $ 405,642 $ 516,134 $ 281,534
Income tax expense statutory tax rate	Year Ended December 31, 2015 2016 2017 Current Tax expense $ 99,816 $ 106,315 $ 63,495 Deferred Tax expense - - - Income taxes $ 99,816 $ 106,315 $ 63,495 Effective tax rate on income / (loss) excluding impairment loss and gain from repurchase of the senior secured notes 24.6 % 20.6 % 22.6 %
Schedule of reconciliation of total tax expense	Year Ended December 31, Reconciliation of total tax expense: 2015 2016 2017 Income tax 94,331 106,315 63,495 Taxes on litigation matters subject to statutory rates, including interest and penalties 5,485 - - Total $ 99,816 $ 106,315 $ 63,495
Schedule of deferred tax assets and liabilities	Year ended December 31, 2016 2017 Deferred tax assets Losses carried forward 10,110 12,176 Total deferred tax assets $ 10,110 $ 12,176 Less: valuation allowance (10,110 ) (12,176 ) Total deferred tax assets, net $ - $ -

Earnings_ (loss) per share (Tab

Earnings/ (loss) per share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings/ (loss) per share:
Earnings / (loss) per share	2015 2016 2017 Income (numerator) Weighted- average number of outstanding shares (denominator) Amount per share Loss (numerator) Weighted- average number of outstanding share (denominator) Amount per share Loss (numerator) Weighted- average number of outstanding shares (denominator) Amount per share Class A Class A Class A Class A Class A Class A Class A Class B Class A Class B Class A Class B Basic net income/ (loss) per share: Net income/ (loss) $ 80,014 - - $ (3,241,518) - - $ (5,366 ) $ (36) - - - - Less: Non- vested common stock dividends declared and undistributed earnings (1,175 ) - - - - - - - - - - - Basic Earnings/ (loss) per share attributable to common stockholders $ 78,839 $ 15,082 5,227.36 $ (3,241,518) 10,538 (307,602.77) $ (5,366 ) $ (36) 25,070,978 167,314 (0.21) (0.21) Diluted net income/ (loss) per share: Allocation of undistributed earnings/ (losses) for basic computation - - - - - - (5,366 ) (36) - - - - Reallocation of undistributed earnings/ (losses) as a result of conversion of Class B to Class A shares - - - - - - - - - - - - Diluted Earnings/ (loss) per share $ 78,839 $ 15,082 5,227.36 $ (3,241,518) 10,538 (307,602.77) $ (5,366 ) $ (36 ) 25,070,978 167,314 (0.21) (0.21)

Geographic information for of41

Geographic information for offshore drilling operations (Tables)	12 Months Ended
	Dec. 31, 2017
Geographic information for offshore drilling operations [Abstract]
Geographic information for offshore drilling operations	Country 2015 2016 2017 Angola 527,098 500,413 435,785 Brazil 581,438 517,885 333,186 Congo 157,235 241,953 185,040 Norway 231,189 74,925 53,509 Falklands 154,606 21,106 - Senegal 52,214 289,162 - Ivory Coast 33,723 1,164 - Other service revenues 10,697 7,059 - Total service revenues $ 1,748,200 1,653,667 1,007,520

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies [Abstract]
Purchase obligations	2018 2019 Total Drilling units building contracts $ 417,931 520,165 $ 938,096 Total obligations $ 417,931 520,165 $ 938,096

Basis of Presentation and Gen43

Basis of Presentation and General Information (Table) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Customer A
Concentration Risk [Line Items]
Major customer revenue percentage	0.00%	11.00%	14.00%
Customer B
Concentration Risk [Line Items]
Major customer revenue percentage	33.00%	20.00%	19.00%
Customer C
Concentration Risk [Line Items]
Major customer revenue percentage	0.00%	0.00%	13.00%
Customer D
Concentration Risk [Line Items]
Major customer revenue percentage	40.00%	31.00%	15.00%
Customer E
Concentration Risk [Line Items]
Major customer revenue percentage	0.00%	14.00%	13.00%
Customer F
Concentration Risk [Line Items]
Major customer revenue percentage	0.00%	18.00%	15.00%

Basis of Presentation and Gen44

Basis of Presentation and General Information (Details)	9 Months Ended
	Sep. 22, 2017	Apr. 05, 2016
Stockholders' Equity, Reverse Stock Split	1-for-9,200 reverse stock split
DryShips
Ownership percentage		0.00%

Significant Accounting Polici45

Significant Accounting Policies - Balance Sheet of additional VIE (Table) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CURRENT ASSETS:
Cash and cash equivalents	$ 736,114	$ 718,684	$ 734,747	$ 528,933
Restricted cash	46,967	34,274
Trade accounts receivable, net	169,651	297,059
Other current assets	37,986	29,924
Total current assets	990,718	1,079,941
FIXED ASSETS, NET:
Drilling units, machinery and equipment, net	1,852,167	2,438,292
Total fixed assets, net	1,852,167	2,983,761
OTHER NON-CURRENT ASSETS:
Restricted cash	0	20,008
Total assets	2,851,965	4,091,544
CURRENT LIABILITIES:
Current portion of long-term debt, net of deferred financing costs	81,632	640,557
Accounts payable and other current liabilities	41,338	53,891
Accrued liabilities	45,018	86,750
Total current liabilities	184,043	812,011
NON-CURRENT LIABILITIES
Long term debt, net of current portion and deferred financing costs	450,000	3,247,216
Total non-current liabilities	464,702	3,268,783
COMMITMENTS AND CONTINGENCIES
SHAREHOLDERS' EQUITY:
Common stock, $20 par value; 1,000 shares authorized and issued at December 31, 2016 and 2017	916	0
Additional paid-in capital	5,722,078	3,525,252
Retained earnings	(3,523,250)	(3,517,848)
Total shareholders' equity	2,203,220	10,750	$ 3,274,765	$ 3,166,276
Total liabilities and shareholders' equity	2,851,965	4,091,544
Drillship Alonissos Stock Trust
CURRENT ASSETS:
Cash and cash equivalents	110	167
Restricted cash	45,339	31,956
Trade accounts receivable, net	0	3,341
Other current assets	1,929	1,884
Total current assets	47,378	37,348
FIXED ASSETS, NET:
Drilling units, machinery and equipment, net	175,362	675,420
Total fixed assets, net	175,362	675,420
OTHER NON-CURRENT ASSETS:
Restricted cash	0	20,008
Total non-current assets, net	0	20,008
Total assets	222,740	732,776
CURRENT LIABILITIES:
Current portion of long-term debt, net of deferred financing costs	81,632	164,218
Accounts payable and other current liabilities	249	5,218
Accrued liabilities	4,416	1,791
Total current liabilities	86,297	171,227
NON-CURRENT LIABILITIES
Long term debt, net of current portion and deferred financing costs	0	82,947
Total non-current liabilities	0	82,947
COMMITMENTS AND CONTINGENCIES
SHAREHOLDERS' EQUITY:
Common stock, $20 par value; 1,000 shares authorized and issued at December 31, 2016 and 2017	20	20
Additional paid-in capital	960	960
Retained earnings	135,463	477,622
Total shareholders' equity	136,443	478,602
Total liabilities and shareholders' equity	$ 222,740	$ 732,776

Significant Accounting Polici46

Significant Accounting Policies - Balance Sheet of additional VIE (Parentheticals) (Details) - $ / shares	Dec. 31, 2017	Sep. 22, 2017	Dec. 31, 2016	Jun. 08, 2015
Common stock par value	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Common stock shares authorized	1,800,000,000		1,000,000,000
Common stock shares issued	91,567,982	8,975	17,486
Drillship Alonissos Stock Trust
Common stock par value	$ 20		$ 20
Common stock shares authorized	1,000		1,000
Common stock shares issued	1,000		1,000

Significant Accounting Polici47

Significant Accounting Policies (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / shares	Dec. 31, 2016USD ($)$ / shares	Dec. 31, 2015USD ($)$ / shares	Feb. 13, 2015USD ($)
Advances for drilling units under construction	$ 0	$ 545,469
Allowance for doubtful receivables	13,526	22,368	$ 117,438
Capitalized interest	27,718	28,265	26,055
Amortization and write off of financing costs	61,212	21,040	24,033
Impairment loss	$ 1,048,828	3,776,338	414,986
Number of reportable segments	1
Net income/ (loss)	$ (5,402)	$ (3,241,518)	$ 80,014
Earnings/(loss) per common share, basic and diluted | $ / shares	$ (0.21)	$ (307,602.77)	$ 5,227.36
Effect of the change in accounting estimate
Net income/ (loss)	$ (14,469)
Earnings/(loss) per common share, basic and diluted | $ / shares	$ (0.57)
Bare deck
Useful life	30 years
Cumulative installment payments made to Samsung
Advances for drilling units under construction	$ 466,258
Number of vessels	2
Drilling Units
Depreciation method	Straight-line basis
Number of vessels	1	8	2
Impairment loss	$ 473,343	$ 3,658,815	$ 414,986
Interval between drilling units special survey	5 years
Ocean Rig Amorgos
Impairment loss		92,371
Ocean Rig Santorini and Ocean Rig Crete
Number of vessels	2
Impairment loss	$ 573,162
Drilling units as held and used
Number of vessels	2
Impairment loss due to reclassification	$ 2,323
Minimum | Other asset parts
Useful life	5 years
Maximum | Other asset parts
Useful life	30 years
Cash flow hedge for interest capitalized on drilling units impaired
Impairment loss		25,152
VIE Supportive to the drilling operation
VIE, total assets	$ 15,029	23,227
VIE, total liabillities	92,622	86,119
VIE, net assets	(77,593)	(62,892)
$462 million Senior Secured Credit Facility
Line of Credit Facility, Maximum Borrowing Capacity	$ 462,000	$ 462,000		$ 475,000

Liquidity and Going Concern c48

Liquidity and Going Concern considerations (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 22, 2017USD ($)shares	Dec. 31, 2017USD ($)shares	Aug. 11, 2017	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Cash and cash equivalents		$ 736,114		$ 718,684	$ 734,747	$ 528,933
Current and non-current restricted cash		46,967		54,282
Working capital surplus		$ 806,675		$ 267,930
Number of terminated drilling contracts		1		5
Number of postponed drilling units		6
Stockholders' Equity, Reverse Stock Split	1-for-9,200 reverse stock split
Common stock shares issued | shares	8,975	91,567,982		17,486
Common stock shares outstanding | shares	8,975	91,567,982		17,486
Prime Cap Shipping Inc.
Debt Instrument [Line Items]
Percentage of shareholder	9.32%
Before the 1-for-9,200 reverse stock split
Debt Instrument [Line Items]
Common stock shares issued | shares	82,586,851			160,888,606
Common stock shares outstanding | shares	82,586,851			160,888,606
New secured debt
Debt Instrument [Line Items]
Face amount		$ 450,000
New secured debt | Upon sanction | Scheme Companies
Debt Instrument [Line Items]
Face amount		450,000
Restructuring Support Agreement (the "RSA") | Scheme Companies
Debt Instrument [Line Items]
Ownership percentage	90.68%
Percentage of Company's outstanding indebtness represented by the creditors			97.00%
Aggregate cash consideration paid (including early consent fee)	$ 320,800
Restructuring Support Agreement (the "RSA") | Scheme Companies | Minimum
Debt Instrument [Line Items]
Percentage represented in Scheme Companies Meetings			75.00%
Restructuring Support Agreement (the "RSA") | Upon sanction | Scheme Companies
Debt Instrument [Line Items]
Principal amount of debt exchanged		3,700,000
Aggregate cash consideration paid (excluding early consent fee)		$ 288,000

Transaction with Related Partie

Transaction with Related Parties - Balance Sheet (Table) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Advances for drilling units under construction and related costs	$ 0	$ 545,469
Drilling units, machinery and equipment, net	1,852,167	2,438,292
Due to related parties	(726)	(7,231)
Accrued liabilities	(45,018)	(86,750)
Related Party
Advances for drilling units under construction and related costs	0	1,569
Drilling units, machinery and equipment, net	0	488
Due to related parties	(726)	(7,231)
Accrued liabilities	$ (11,786)	$ (3,100)

Transaction with Related Part50

Transaction with Related Parties - Statement of Operations (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Drilling units operating expenses	$ 295,135	$ 454,329	$ 582,122
Amortization and write-off of financing fees	61,212	21,040	24,033
General and administrative expenses	73,360	103,961	100,314
Reorganization expenses (including non-cash issuance of shares and other expenses)	1,029,982	0	0
Related Party
Revenues - commission fees	10,342	14,925	16,524
Drilling units operating expenses	904	4,209	0
Amortization and write-off of financing fees	0	0	2,781
General and administrative expenses	26,008	24,924	7,409
Interest income	0	0	6,024
Reorganization expenses (including non-cash issuance of shares and other expenses)	$ 223,178	$ 0	$ 0

Transactions with Related Par51

Transactions with Related Parties (Details) - USD ($) $ in Thousands	3 Months Ended		5 Months Ended	7 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2017	Apr. 05, 2016	Jun. 08, 2015	Aug. 13, 2015	Sep. 22, 2017	Dec. 31, 2017	Dec. 31, 2015	Dec. 31, 2016	Nov. 18, 2014
Related Party Transaction [Line Items]
Refundable security deposit held in escrow	$ 5,000					$ 5,000		$ 0
Issuance of common stock, shares			3,106		90,651,603
Common stock shares outstanding	91,567,982				8,975	91,567,982		17,486
Chairman
Related Party Transaction [Line Items]
Issuance of common stock, shares			155,299
Common stock shares outstanding	8,525,596					8,525,596
Percentage of shareholder	9.30%					9.30%
Before the 1-for-9,200 reverse stock split
Related Party Transaction [Line Items]
Issuance of common stock, shares			28,571,428
Common stock shares outstanding					82,586,851			160,888,606
Before the 1-for-9,200 reverse stock split | Chairman
Related Party Transaction [Line Items]
Issuance of common stock, shares			1,428,571
Steel Wheel Investments Limited
Related Party Transaction [Line Items]
Ownership in Ocean Rig						170
Steel Wheel Investments Limited | Before the 1-for-9,200 reverse stock split
Related Party Transaction [Line Items]
Ownership in Ocean Rig						1,570,226
DryShips Inc.
Related Party Transaction [Line Items]
Unsecured debt to former parent company									$ 120,000
Treasury Stock, Shares, Acquired		6,096
DryShips Inc. | Before the 1-for-9,200 reverse stock split
Related Party Transaction [Line Items]
Treasury Stock, Shares, Acquired		56,079,533
TMS Offshore Services Ltd.
Related Party Transaction [Line Items]
Total charges						$ 45,521
TMS Offshore Services Ltd. | Restructuring plan
Related Party Transaction [Line Items]
Fees on monies earned under drilling contracts	1.00%
Termination fee	$ 150,000
Termination fee, lowest threshold	30,000
Annual fee	15,500
Additional fee based on satisfaction of certain metrics	$ 10,000
TMS Offshore Services Ltd. | Restructuring plan | Upon any cause
Related Party Transaction [Line Items]
Period required for cancellation written notice for agreement	5 days
Termination fee	$ 50,000
Refundable security deposit held in escrow	$ 5,000					$ 5,000
Prime Cap Shipping Inc.
Related Party Transaction [Line Items]
Issuance of common stock, shares					8,524,793
Percentage of shareholder					9.32%
Global Services Agreement January 2013 | Cardiff Drilling Inc.
Related Party Transaction [Line Items]
Termination date of agreement						Mar. 31, 2016
Consultancy Agreement January 2013 | Vivid Finance Limited
Related Party Transaction [Line Items]
Termination date of agreement						Mar. 31, 2016
Consultancy Agreement January 2013 | Azara Services S.A.
Related Party Transaction [Line Items]
Termination date of agreement						Dec. 31, 2016
Consultancy Agreement 2012 | Basset
Related Party Transaction [Line Items]
Termination date of agreement						Dec. 31, 2016
Ownership in Ocean Rig						12
Consultancy Agreement 2012 | Basset | Before the 1-for-9,200 reverse stock split
Related Party Transaction [Line Items]
Ownership in Ocean Rig						114,286
Exchange of $120.0 million Exchangeable Promissory Note | DryShips Inc.
Related Party Transaction [Line Items]
Debt facility, Amount exchanged							$ 120,000
Treasury Stock, Shares, Acquired				1,932			2,415
Exchange of $120.0 million Exchangeable Promissory Note | DryShips Inc. | Before the 1-for-9,200 reverse stock split
Related Party Transaction [Line Items]
Treasury Stock, Shares, Acquired				17,777,778			22,222,222
Crescendo and Jubilee | DryShips Inc.
Related Party Transaction [Line Items]
Duration of time charter agreement						60 days

Other Current Assets (Table) (D

Other Current Assets (Table) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Current Assets [Abstract]
Inventories	$ 9,573	$ 12,988
Deferred mobilization expenses	6,482	6,351
Prepayments and advances	17,064	10,500
Intangible assets, net	402	0
Insurance claims	2,980	0
Other	1,485	85
Total	$ 37,986	$ 29,924

Advances for drilling units u53

Advances for drilling units under construction and related costs (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Balance at beginning of year	$ 545,469
Impairment loss (advances and related costs for drilling unit under construction)	(1,048,828)	$ (3,776,338)	$ (414,986)
Balance at end of year	0	545,469
Advances for drilling units under construction
Property, Plant and Equipment [Line Items]
Balance at beginning of year	545,469	394,852
Advances for drilling units under construction and related costs	27,693	242,988
Impairment loss (advances and related costs for drilling unit under construction)	(573,162)	(92,371)
Balance at end of year	$ 0	$ 545,469	$ 394,852

Advances for drilling units u54

Advances for drilling units under construction and related costs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Advances for drilling units under construction	$ 0	$ 545,469
Impairment loss	1,048,828	3,776,338	$ 414,986
Ocean Rig Santorini
Price per drilling unit	694,790
Advances for drilling units under construction	309,358
Ocean Rig Crete
Price per drilling unit	709,565
Advances for drilling units under construction	$ 156,900
Ocean Rig Amorgos
Impairment loss		$ 92,371
Ocean Rig Santorini and Ocean Rig Crete
Number of vessels	2
Impairment loss	$ 573,162
Yard
Construction contracts, Agreement terms	The Company entered into agreements with the yard to amend certain terms relating to contracts for the construction of its three seventh generation drilling units (the Ocean Rig Santorini, the Ocean Rig Crete and the Ocean Rig Amorgos) which were previously scheduled for delivery in 2017, 2018 and 2019, respectively.
Yard | Ocean Rig Crete
Construction contracts, Agreement terms	As part of the agreements, the deliveries of the Ocean Rig Santorini and the Ocean Rig Crete were postponed to June 2018 and January 2019, respectively.
Yard | Prior amendment of August 11, 2016 | Ocean Rig Santorini
Drilling Unit delivery	2,017
Yard | Prior amendment of August 11, 2016 | Ocean Rig Crete
Drilling Unit delivery	2,018
Yard | Prior amendment of August 11, 2016 | Ocean Rig Amorgos
Drilling Unit delivery	2,019
Yard | After amendment of August 11, 2016 | Ocean Rig Santorini
Drilling Unit delivery	June 2,018
Yard | After amendment of August 11, 2016 | Ocean Rig Crete
Drilling Unit delivery	January 2,019
Yard | After amendment of August 11, 2016 | Ocean Rig Amorgos
Drilling Unit delivery	suspended
Yard | After amendment of August 11, 2016 - Company's option | Ocean Rig Amorgos
Construction contracts, Agreement terms	With respect to the Ocean Rig Amorgos, the Company had previously agreed to suspend its construction with an option, subject to the Company's option, to bring it back into force within a period of 18 months after the date of the addendum, which option expired in February 2018.

Drilling units, machinery and55

Drilling units, machinery and equipment, net (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Balance	$ 2,438,292
Impairment loss	1,048,828	$ 3,776,338	$ 414,986
Balance	1,852,167	2,438,292
Drilling units, machinery and equipment | Cost
Property, Plant and Equipment [Line Items]
Balance	3,691,939	7,258,995
Additions	9,726	99,515
Disposal of assets	(1,648)	(7,756)
Impairment loss	(475,666)	(3,658,815)
Balance	3,224,351	3,691,939	7,258,995
Drilling units, machinery and equipment | Accumulated Depreciation
Property, Plant and Equipment [Line Items]
Balance	(1,253,647)	(922,103)
Disposal of assets	1,212	133
Depreciation	(119,749)	(331,677)
Balance	(1,372,184)	(1,253,647)	(922,103)
Drilling units, machinery and equipment | Net Book Value
Property, Plant and Equipment [Line Items]
Balance	2,438,292	6,336,892
Additions	9,726	99,515
Disposal of assets	(436)	(7,623)
Impairment loss	(475,666)	(3,658,815)
Depreciation	(119,749)	(331,677)
Balance	$ 1,852,167	$ 2,438,292	$ 6,336,892

Drilling units, machinery and56

Drilling units, machinery and equipment, net (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Feb. 13, 2015USD ($)
Impairment loss	$ 1,048,828	$ 3,776,338	$ 414,986
Debt Instrument, Collateral	As of December 31, 2017, all of the Company's drilling units have been pledged as collateral to secure the Company's $450,000 and $462,000 Senior Secured Credit Facilities, as discussed in Note 9.
Drilling Units
Number of vessels	1	8	2
Impairment loss	$ 473,343	$ 3,658,815	$ 414,986
Drilling units as held and used
Number of vessels	2
Impairment loss due to reclassification	$ 2,323
$462 million Senior Secured Credit Facility
Original Amount	462,000	$ 462,000		$ 475,000
$450 million Senior Secured Term Loan Facility
Original Amount	$ 450,000

Other non-current assets (Tab57

Other non-current assets (Table) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other non-current assets [Abstract]
Deferred mobilization expenses	$ 4,080	$ 5,564
Intangible assets, net	0	1,845
Prepaid investments	0	425
Security deposit	5,000	0
Total	$ 9,080	$ 7,834

Long-term Debt (Table) (Details

Long-term Debt (Table) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Total principal payments	$ 531,886	$ 3,949,239
Less: Deferred financing costs	(254)	(61,466)
Total debt	531,632	3,887,773
Less: Current portion	(81,632)	(640,557)
Long-term portion	450,000	3,247,216
$1.3 billion Senior Secured Term Loan B Facility
Debt Instrument [Line Items]
Total principal payments	0	1,270,750
$1.9 billion Secured Term Loan B Facility
Debt Instrument [Line Items]
Total principal payments	0	1,838,250
$800 million Senior Secured Notes
Debt Instrument [Line Items]
Total principal payments	0	459,723
$450 million Senior Secured Term Loan Facility
Debt Instrument [Line Items]
Total principal payments	450,000	0
$462 million Senior Secured Credit Facility
Debt Instrument [Line Items]
Total principal payments	81,886	249,542
$500 million Senior Unsecured Notes
Debt Instrument [Line Items]
Total principal payments	$ 0	$ 130,974

Long-term Debt - Loan Movements

Long-term Debt - Loan Movements (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Feb. 13, 2015	Jul. 12, 2013
Debt Instrument [Line Items]
December 31, 2016	$ 3,949,239
New Loan	450,000
Discharges/ Repayment	(3,867,353)
December 31, 2017	$ 531,886
$800 million Senior Secured Notes
Debt Instrument [Line Items]
Loan Agreement Date	Sep. 20, 2012
Original Amount	$ 800,000
December 31, 2016	459,723
Discharges/ Repayment	(459,723)
December 31, 2017	$ 0
$1.9 billion Secured Term Loan B Facility
Debt Instrument [Line Items]
Loan Agreement Date	Jul. 12, 2013
Original Amount	$ 1,900,000			$ 1,800,000
December 31, 2016	1,838,250
Discharges/ Repayment	(1,838,250)
December 31, 2017	$ 0
$1.3 billion Senior Secured Term Loan B
Debt Instrument [Line Items]
Loan Agreement Date	Jul. 25, 2014
Original Amount	$ 1,300,000
December 31, 2016	1,270,750
Discharges/ Repayment	(1,270,750)
December 31, 2017	$ 0
$450 million Senior Secured Term Loan Facility
Debt Instrument [Line Items]
Loan Agreement Date	Sep. 22, 2017
Original Amount	$ 450,000
December 31, 2016	0
New Loan	450,000
December 31, 2017	$ 450,000
$500 million Senior Unsecured Notes
Debt Instrument [Line Items]
Loan Agreement Date	Mar. 26, 2014
Original Amount	$ 500,000
December 31, 2016	130,974
Discharges/ Repayment	(130,974)
December 31, 2017	$ 0
$462 million Senior Secured Credit Facility
Debt Instrument [Line Items]
Loan Agreement Date	Feb. 13, 2015
Original Amount	$ 462,000	$ 462,000	$ 475,000
December 31, 2016	249,542
Discharges/ Repayment	(167,656)
December 31, 2017	$ 81,886

Long-term Debt - Principal Paym

Long-term Debt - Principal Payments (Table) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Long-term Debt, by Maturity [Abstract]
2,018	$ 81,886
2,019	0
2,020	0
2,021	0
2,022	0
2023 and thereafter	450,000
Total principal payments	531,886	$ 3,949,239
Less: Financing fees	(254)	(61,466)
Total debt	$ 531,632	$ 3,887,773

Long-term Debt - Debt discharge

Long-term Debt - Debt discharged during 2017 (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	7 Months Ended	9 Months Ended	12 Months Ended
	Mar. 26, 2014	Jul. 12, 2013	Jul. 25, 2014	Sep. 22, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Proceeds from Issuance of Debt					$ 0	$ 0	$ 462,000
Repayment of debt					496,457	215,279	61,179
Gain from repurchase of senior notes					0	125,001	189,174
Issuance of common stock, value					2,197,128		193,983
Reorganization Gain, net					$ 1,029,982	0	$ 0
7.25% Senior Unsecured Notes
Debt Instrument [Line Items]
Debt Instrument, Issuance Date					Mar. 26, 2014
Principal amount					$ 500,000
Interest rate					7.25%
Proceeds from Issuance of Debt	$ 493,625
Debt Instrument, Repurchased Face Amount						369,026
Debt instrument frequency of periodic payment					semi-annual
Gain from repurchase of senior notes						57,160
Repurchase date					Mar. 21, 2017
9.5% Senior Unsecured Notes
Debt Instrument [Line Items]
Interest rate					9.50%
Repayment of debt	$ 462,300
6.5% Senior Secured Notes
Debt Instrument [Line Items]
Debt Instrument, Issuance Date					Sep. 20, 2012
Principal amount					$ 800,000
Interest rate					6.50%
Debt Instrument, Repurchased Face Amount						148,019
Debt instrument frequency of periodic payment					semi-annual
Gain from repurchase of senior notes						$ 67,841
Repurchase date					Mar. 21, 2017
$1.3 billion Senior Secured Term Loan B Facility
Debt Instrument [Line Items]
Debt Instrument, Issuance Date					Jul. 25, 2014
Principal amount					$ 1,300,000
Maturity date					Jul. 25, 2021
$1.35 billion Senior Secured Credit Facility
Debt Instrument [Line Items]
Repayment of debt			$ 1,300,000
$1.9 billion Secured Term Loan B Facility
Debt Instrument [Line Items]
Debt Instrument, Issuance Date					Jul. 12, 2013
Principal amount		$ 1,800,000			$ 1,900,000
Maturity date of loan					Q3 2020
$1.9 billion Secured Term Loan B Facility | Tranche B1 term loans
Debt Instrument [Line Items]
Principal amount		$ 975,000
Maturity date of loan		Q1 2021
$1.9 billion Secured Term Loan B Facility | Tranche B2 term loans
Debt Instrument [Line Items]
Principal amount		$ 825,000
Maturity date of loan		Q3 2016
$1.9 billion Secured Term Loan B Facility | Additional Tranche B1 Term Loans
Debt Instrument [Line Items]
Debt Instrument, Issuance Date					Jul. 26, 2013
Principal amount					$ 100,000
Maturity date description					On February 7, 2014, the Company refinanced its then existing short-term Tranche B-2 with a fungible add-on to its existing long-term Tranche B-1 with maturity date at no earlier than the third quarter of 2020.
7.25% Senior Unsecured Notes, 6.50% Senior Secured Notes, $1.3 billion Senior Secured Term Loan B Facility and $1.9 billion Term Loan B Facility
Debt Instrument [Line Items]
Issuance of common stock, value				$ 1,992,533
Aggregate cash consideration paid (including early consent fee)				320,800
Reorganization Gain, net				$ 1,129,125

Long-term Debt - Term bank loan

Long-term Debt - Term bank loans/ Credit facilities (Details) - USD ($) $ in Thousands	2 Months Ended	12 Months Ended
	Mar. 03, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 31, 2016	Aug. 22, 2016	Feb. 13, 2015
Debt Instrument [Line Items]
Repayment of debt		$ 496,457	$ 215,279	$ 61,179
$450 million Senior Secured Term Loan Facility
Debt Instrument [Line Items]
Debt Instrument, Issuance Date		Sep. 22, 2017
Debt Instrument, Face Amount		$ 450,000
Debt Instrument, Maturity Date		Sep. 20, 2024
Interest rate		8.00%
Covenant terms		The New Credit Agreement contains limited restrictive covenants that are usual and customary for facilities of this type, including, without limitation: (i) delivery of financial statements, reports, accountants' letters, certificates and SEC filings; (ii) notices of defaults, material litigation and other material events; (iii) continuation of business and maintenance of existence and material rights and privileges; (iv) compliance with laws, including sanctions laws; and (v) maintenance of property and insurance.
$450 million Senior Secured Term Loan Facility | Until March 22, 2018
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage		100.00%
$450 million Senior Secured Term Loan Facility | From March 23, 2018 until March 22, 2019
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage		105.00%
$450 million Senior Secured Term Loan Facility | From March 23, 2019 until March 22, 2020
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage		103.00%
$450 million Senior Secured Term Loan Facility | From March 23, 2020 until March 22, 2021
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage		101.00%
$462 million Senior Secured Credit Facility
Debt Instrument [Line Items]
Debt Instrument, Issuance Date		Feb. 13, 2015
Line of Credit Facility, Maximum Borrowing Capacity		$ 462,000	$ 462,000				$ 475,000
Amount drawn down	$ 462,000
Debt Instrument, Term		5 years
Variable rate basis		LIBOR
Debt Instrument, Maturity Date		Jun. 30, 2018
Covenant terms		Under the $462,000 Senior Secured Credit Facility, the Company was required to find a new Satisfactory Drilling Contract (as defined in the loan agreement) by May 21, 2016.
Mandatory prepayment of debt						$ 145,894
Amended mandatory prepayment amount					$ 125,000
Long-term Debt, Maturities, Repayment Terms		The repayment schedule of the loan was altered to include a cash sweep term authorizing the lenders to transfer any excess cash flow on a monthly basis, as a prepayment pro rata across the loan, therefore, leading to the full repayment of the loan by June 2018, whereas according to the initial repayment schedule it would have been fully repaid by June 2020.

Long-term Debt - Additional Inf

Long-term Debt - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt [Abstract]
Interest expense	$ 275,494	$ 256,222	$ 300,543
Capitalized interest	$ 27,718	$ 28,265	$ 26,055
Weighted average interest rate	6.90%	6.20%	6.30%

Financial Instruments and Fai64

Financial Instruments and Fair Value Measurements - Derivatives Not Designated as Hedging Instruments on the Consolidated Statement of Operations (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Loss on interest rate swaps	$ 0	$ (4,388)	$ (11,513)
Interest rate swaps | Derivatives not designated or qualifying as Hedging Instruments
Derivative [Line Items]
Loss on interest rate swaps	$ 0	$ (4,388)	$ (11,513)

Financial Instruments and Fai65

Financial Instruments and Fair Value Measurements - Measured on a Non-recurring basis (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Impairment loss	$ (1,048,828)	$ (3,776,338)	$ (414,986)
On a non-recurring basis
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Impairment loss	(475,666)	(3,658,815)
On a non-recurring basis | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Line Items]
Long-lived assets	$ 234,139	$ 1,035,499

Financial Instruments and Fai66

Financial Instruments and Fair Value Measurements - Interest Rate Swaps (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2010USD ($)
Interest rate swaps and cap floor agreements:
Reclassification of realized losses associated with capitalized interest to the Consolidated Statement of Operations (Note 10)	$ 0	$ 26,187	$ 1,035
Cash flow hedge realized
Interest rate swaps and cap floor agreements:
(Unrealized) / realized losses on cash flow hedges accumulated in other comprehensive income				$ 27,776
Interest Rate Swaps
Interest rate swaps and cap floor agreements:
Number of interest rate swap held	0		7
Notional amount of interest rate swaps			$ 1,600,000
Discussion of Method of Measuring Fair Value of Interest Rate Derivatives	The fair value of the interest rate swaps was determined using a discounted cash flow method based on market-based LIBOR swap yield curves, taking into account current interest rates and the creditworthiness of both the financial instrument counterparty and the Company.

Financial Instruments and Fai67

Financial Instruments and Fair Value Measurements - Senior Notes and Credit Facilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Senior notes and credit facilities:
Debt instrument - carrying value, net of financing fees	$ 531,632	$ 3,887,773
7.25% Senior Unsecured Notes
Senior notes and credit facilities:
Debt instrument - estimated fair value		51,080	$ 100,367
Debt instrument - carrying value, net of financing fees		129,844	226,655
$462 million Senior Secured Credit Facility
Senior notes and credit facilities:
Debt instrument description	LIBOR
$450 million Senior Secured Term Loan Facility
Senior notes and credit facilities:
Debt instrument - estimated fair value	$ 456,000
Drill Rigs Senior Notes
Senior notes and credit facilities:
Debt instrument - estimated fair value		201,129	357,431
Debt instrument - carrying value, net of financing fees		457,745	601,845
$1.9 billion Secured Term Loan B Facility
Senior notes and credit facilities:
Debt instrument - estimated fair value		1,156,958	427,168
Debt instrument - carrying value, net of financing fees		1,804,272	1,814,746
1.3 billion Senior Secured Term Loan B Facility
Senior notes and credit facilities:
Debt instrument - estimated fair value		1,002,304	628,242
Debt instrument - carrying value, net of financing fees		$ 1,248,747	$ 1,257,484

Financial Instruments and Fai68

Financial Instruments and Fair Value Measurements (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 22, 2017$ / shares
Carrying amount	$ 1,852,167	$ 2,983,761
Impairment loss	1,048,828	3,776,338	$ 414,986
Price per share | $ / shares				$ 24
Drilling Units
Carrying amount	$ 650,843	$ 4,694,314
Number of vessels	1	8	2
Impairment loss	$ 473,343	$ 3,658,815	$ 414,986
Drilling units as held and used
Carrying amount	$ 56,639
Number of vessels	2
Impairment loss due to reclassification	$ 2,323
Ocean Rig Amorgos
Impairment loss		92,371
Ocean Rig Santorini and Ocean Rig Crete
Number of vessels	2
Impairment loss	$ 573,162
Cash flow hedge for interest capitalized on drilling units impaired
Impairment loss		$ 25,152

Common Stock and Additional P69

Common Stock and Additional Paid-in Capital - Non-Vested and Vested Shares (Table) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Number of non vested shares
Balance	11	44
Granted	12,000
Forfeited		(17)
Vested	(12,011)	(16)
Balance	0	11
Weighted average grant date fair value per non vested shares
Balance	$ 87,032	$ 99,360
Granted	25.56
Forfeited		92,736
Vested	105.24	114,356
Balance	$ 0	$ 87,032
Number of vested shares
Balance	37	66
Vested shares granted in prior years	11	16
Granted and vested shares in prior years, but cancelled during 2016		(45)
Vested shares granted in 2017	12,000
Balance	12,048	37
Weighted average grant date fair value per vested shares
Balance	$ 146,648	$ 139,380
Vested shares granted in prior years	87,032	114,356
Granted and vested shares in prior years, but cancelled during 2016		124,384
Vested shares granted in 2017	25.56
Balance	$ 558.94	$ 146,648

Common Stock and Additional P70

Common Stock and Additional Paid-in Capital - General - Dividends - Reverse stock splits (Details) - $ / shares	4 Months Ended	9 Months Ended	12 Months Ended
	Apr. 24, 2017	Sep. 22, 2017	Dec. 31, 2017	Nov. 03, 2017	Dec. 31, 2016	Jun. 08, 2015
Common stock shares authorized			1,800,000,000		1,000,000,000
Preferred stock shares authorized			100,000,000		500,000,000
Common stock par value		$ 0.01	$ 0.01		$ 0.01	$ 0.01
Preferred stock par value			$ 0.01		$ 0.01
Stockholders' Equity, Reverse Stock Split		1-for-9,200 reverse stock split
Installment 4 - FY 2014
Dividend Payable Date To Be Paid Day Month And Year			Mar. 23, 2015
Share price of dividend paid			$ 0.19
Installment 1 - FY 2015
Dividend Payable Date To Be Paid Day Month And Year			May 29, 2015
Share price of dividend paid			$ 0.19
Common Class A
Common stock shares authorized			1,500,000,000
Common Class B
Common stock shares authorized			300,000,000
Annual General Meeting
Common stock shares authorized	1,000,000,000,000
Preferred stock shares authorized	500,000,000
Common stock par value	$ 0.01
Preferred stock par value	$ 0.01
Annual General Meeting | Minimum
Stockholders' Equity, Reverse Stock Split	1-for-2 reverse stock split
Annual General Meeting | Maximum
Stockholders' Equity, Reverse Stock Split	1-for-100,000 reverse stock split
Extraordinary General Meeting | Second Amended and Restated Memorandum
Common stock shares authorized				1,800,000,000
Preferred stock shares authorized				100,000,000
Preferred stock par value				$ 0.01
Extraordinary General Meeting | Second Amended and Restated Memorandum | Common Class A
Common stock shares authorized				1,500,000,000
Common stock par value				$ 0.01
Extraordinary General Meeting | Second Amended and Restated Memorandum | Common Class B
Common stock shares authorized				300,000,000
Common stock par value				$ 0.01

Common Stock and Additional P71

Common Stock and Additional Paid-in Capital - Issuance of common shares and Treasury stock (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	5 Months Ended	7 Months Ended	9 Months Ended	10 Months Ended		12 Months Ended
	Apr. 05, 2016	Jun. 08, 2015	Aug. 13, 2015	Sep. 22, 2017	Nov. 13, 2017	Nov. 03, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Issuance of common stock, shares		3,106		90,651,603
Issuance of common stock, value							$ 2,197,128		$ 193,983
Common stock par value		$ 0.01		$ 0.01			$ 0.01	$ 0.01
Net proceeds from common stock issuance		$ 194,134					$ 0	$ 0	$ 192,714
Price per share				$ 24
Common stock shares outstanding				8,975			91,567,982	17,486
Chairman
Issuance of common stock, shares		155,299
Common stock shares outstanding							8,525,596
Common stock value purchased		$ 10,000
Creditors Scheme
Issuance of common stock, value				$ 1,992,533
Prime Cap Shipping Inc.
Issuance of common stock, shares				8,524,793
Issuance of common stock, value				$ 204,595
DryShips Inc.
Treasury stock, shares	6,096
DryShips Inc. | Exchange of $120.0 million Exchangeable Promissory Note
Treasury stock, shares			1,932						2,415
Principal amount of debt exchanged									$ 120,000
Common Class A
Issuance of common stock, shares							90,663,603		3,106
Issuance of common stock, value							$ 907		$ 0
Conversion of shares, shares converted							337,533
Conversion of shares, shares issued							227,093
Common stock shares outstanding							90,562,138
Common Class B
Issuance of common stock, shares							895,404
Issuance of common stock, value							$ 9
Conversion of shares, shares converted							227,093
Conversion of shares, shares issued							337,533
Common stock shares outstanding							1,005,844
Conversion basis of common stock							one-for-one basis
Extraordinary General Meeting | Second Amended and Restated Memorandum | Common Class A
Common stock par value						$ 0.01
Conversion of shares, shares converted					337,533
Extraordinary General Meeting | Second Amended and Restated Memorandum | Common Class B
Issuance of common stock, shares						895,404
Common stock par value						$ 0.01
Conversion of shares, shares issued					337,533
Before the 1-for-9,200 reverse stock split
Issuance of common stock, shares		28,571,428
Price per share		$ 7
Common stock shares outstanding				82,586,851				160,888,606
Before the 1-for-9,200 reverse stock split | Chairman
Issuance of common stock, shares		1,428,571
Before the 1-for-9,200 reverse stock split | DryShips Inc.
Treasury stock, shares	56,079,533
Before the 1-for-9,200 reverse stock split | DryShips Inc. | Exchange of $120.0 million Exchangeable Promissory Note
Treasury stock, shares			17,777,778						22,222,222

Common Stock and Additional P72

Common Stock and Additional Paid-in Capital - Restricted Stock Awards (Details) - USD ($) $ in Thousands	12 Months Ended			24 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Nov. 14, 2017
Shares granted	12,000
Granted and vested					4,000
Unrecognized compensation cost	$ 0	$ 314	$ 2,299	$ 314
Compensation cost allocated in "General and administrative expenses"	$ 314	$ 1,506	$ 3,676
Employees | 2012 Equity Incentive Plan
Shares granted				20
Employees | 2012 Equity Incentive Plan | Before the 1-for-9,200 reverse stock split
Shares granted				186,702

Accumulated Other Comprehensi73

Accumulated Other Comprehensive Income (Table) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Actuarial pension gain	$ 3,476	$ 3,346
Total	$ 3,476	$ 3,346

Interest and Finance Costs (T74

Interest and Finance Costs (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest and Finance Costs [Abstract]
Interest costs on long term debt	$ 214,282	$ 235,182	$ 276,510
Amortization and write off of financing fees	61,212	21,040	24,033
Discount on receivable from drilling contract	(308)	(2,821)	3,018
Capitalized borrowing costs	(27,718)	(28,265)	(26,055)
Commissions, commitment fees and other financial expenses	874	1,845	2,842
Total	$ 248,342	$ 226,981	$ 280,348

Income Taxes - Income Component

Income Taxes - Income Components (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Foreign income			$ 0
Total income before taxes, excluding impairment loss, gain from repurchases of senior notes, reorganization gain, net and loss from issuance of shares upon restructuring	$ 281,534	$ 516,134	405,642
Marshall Islands
Domestic income/ (loss)			219,900
Foreign income			$ 185,742
Cayman Islands
Domestic income/ (loss)	(276,471)
Foreign income	$ 558,005
January 1, 2016 - April 14, 2016 | Marshall Islands
Domestic income/ (loss)		126,244
Foreign income		93,633
April 15, 2016 - December 31, 2016 | Cayman Islands
Domestic income/ (loss)		(97,939)
Foreign income		$ 394,196

Income Taxes - Tax Component (T

Income Taxes - Tax Component (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Abstract]
Current Tax expense	$ 63,495	$ 106,315	$ 99,816
Deferred Tax expense	0	0	0
Income taxes	$ 63,495	$ 106,315	$ 99,816
Effective tax rate on income / (loss) excluding impairment loss and gain from repurchase of the senior secured notes	22.60%	20.60%	24.60%

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of total tax expense (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of total tax expense:
Income tax	$ 63,495	$ 106,315	$ 94,331
Taxes on litigation matters subject to statutory rates, including interest and penalties	0	0	5,485
Total	$ 63,495	$ 106,315	$ 99,816

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets And Liabilities (Table) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets
Losses carried forward	$ 12,176	$ 10,110
Total deferred tax assets	12,176	10,110
Less: valuation allowance	(12,176)	(10,110)
Total deferred tax assets, net	$ 0	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current liability for corporate income tax	$ 10,994	$ 8,991
Angola, Brazil and Congo
Current tax expense percentage	92.00%
Angola, Brazil, Norway, Congo and Senegal
Current tax expense percentage		93.00%
Angola, Brazil, Norway and Congo
Current tax expense percentage			90.00%
Marshall Islands
Tax rate		0.00%	0.00%
Cayman Islands
Tax rate	0.00%	0.00%

Earnings_ (loss) per share (T80

Earnings/ (loss) per share (Table) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic net income/ (loss) per share:
Net income / (loss)	$ (5,402)	$ (3,241,518)	$ 80,014
Class A
Basic net income/ (loss) per share:
Net income / (loss)	(5,366)	(3,241,518)	80,014
Less: Non-vested common stock dividends declared and undistributed earnings			(1,175)
Income / (Loss) (numerator)	$ (5,366)	$ (3,241,518)	$ 78,839
Weighted- average number of outstanding shares (denominator)	25,070,978	10,538	15,082
Basic Earnings/ (loss) per share attributable to common stockholders	$ (0.21)	$ (307,602.77)	$ 5,227.36
Diluted net income/ (loss) per share:
Allocation of undistributed earnings/ (losses) for basic computation	$ (5,366)
Income / (Loss) (numerator)	$ (5,366)	$ (3,241,518)	$ 78,839
Weighted- average number of outstanding shares (denominator)	25,070,978	10,538	15,082
Diluted Earnings/ (loss) per share	$ (0.21)	$ (307,602.77)	$ 5,227.36
Class B
Basic net income/ (loss) per share:
Net income / (loss)	$ (36)
Income / (Loss) (numerator)	$ (36)
Weighted- average number of outstanding shares (denominator)	167,314
Basic Earnings/ (loss) per share attributable to common stockholders	$ (0.21)
Diluted net income/ (loss) per share:
Allocation of undistributed earnings/ (losses) for basic computation	$ (36)
Income / (Loss) (numerator)	$ (36)
Weighted- average number of outstanding shares (denominator)	167,314
Diluted Earnings/ (loss) per share	$ (0.21)

Geographic information for of81

Geographic information for offshore drilling operations - Revenue per country (Table) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other service revenues	$ 0	$ 7,059	$ 10,697
Total service revenues	1,007,520	1,653,667	1,748,200
Angola
Total service revenues	435,785	500,413	527,098
Brazil
Total service revenues	333,186	517,885	581,438
Congo
Total service revenues	185,040	241,953	157,235
Norway
Total service revenues	53,509	74,925	231,189
Falklands
Total service revenues	0	21,106	154,606
Senegal
Total service revenues	0	289,162	52,214
Ivory Coast
Total service revenues	$ 0	$ 1,164	$ 33,723

Commitments and Contingencies -

Commitments and Contingencies - Purchase Obligations (Table) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Unrecorded Unconditional Purchase Obligation [Line Items]
2,018	$ 417,931
2,019	520,165
Total	938,096
Drilling units building contracts
Unrecorded Unconditional Purchase Obligation [Line Items]
2,018	417,931
2,019	520,165
Total	$ 938,096

Commitments and Contingencies83

Commitments and Contingencies - Legal proceedings (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 22, 2016GBP (£)
Legal Matters and Contingencies [Line Items]
Legal settlements and other, net	$ 1,519	$ 8,720	$ 2,591
Mayze Services Limited ("Mayze")
Legal Matters and Contingencies [Line Items]
Open legal cases claim | £				£ 5,230,074
Legal settlements and other, net	$ 4,000

Subsequent Events (Details)

Subsequent Events (Details) - $ / shares	2 Months Ended	10 Months Ended	12 Months Ended
	Feb. 28, 2018	Nov. 13, 2017	Dec. 31, 2017	Nov. 03, 2017	Sep. 22, 2017	Dec. 31, 2016	Jun. 08, 2015
Subsequent Event [Line Items]
Common stock par value			$ 0.01		$ 0.01	$ 0.01	$ 0.01
Class A Common Shares
Subsequent Event [Line Items]
Conversion of shares, shares converted			337,533
Conversion of shares, shares issued			227,093
Class B Common Shares
Subsequent Event [Line Items]
Conversion of shares, shares converted			227,093
Conversion of shares, shares issued			337,533
Conversion basis of common stock			one-for-one basis
Extraordinary General Meeting | Second Amended and Restated Memorandum | Class A Common Shares
Subsequent Event [Line Items]
Conversion of shares, shares converted		337,533
Common stock par value				$ 0.01
Extraordinary General Meeting | Second Amended and Restated Memorandum | Class B Common Shares
Subsequent Event [Line Items]
Conversion of shares, shares issued		337,533
Common stock par value				$ 0.01
Subsequent event | Extraordinary General Meeting | Second Amended and Restated Memorandum | Class A Common Shares
Subsequent Event [Line Items]
Conversion of shares, shares issued	349,711
Common stock par value	$ 0.01
Subsequent event | Extraordinary General Meeting | Second Amended and Restated Memorandum | Class B Common Shares
Subsequent Event [Line Items]
Conversion of shares, shares converted	349,711
Common stock par value	$ 0.01