Line of credit facility debt to tangible capitalization ratio.

No definition available.

Name:	ne_LineOfCreditFacilityDebtToTangibleCapitalizationRatio
Namespace Prefix:	ne_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line Of Credit Facility Debt To Tangible Capitalization Ratio Covenant.

+ References

No definition available.

+ Details

Name:	ne_LineOfCreditFacilityDebtToTangibleCapitalizationRatioCovenant
Namespace Prefix:	ne_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Incremental percentage increase (decrease) in the stated rate on a debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentInterestRateIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value amount of debt instrument that was repurchased.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRepurchaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRepurchasedFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629

+ Details

Name:	us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfUnsecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=ne_SeniorNotes7.70DueApril2025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ne_SeniorNotes8.70DueApril2045Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ne_SeniorNotes4.90DueAugust2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ne_SeniorNotes4.625DueMarch2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ne_SeniorNotesSevenAndSeniorNoteEightMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ne_SeniorNotes2.50DueMarch2017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ne_SeniorNotes5.75DueMarch2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ne_SeniorNotes3.95DueMarch2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ne_SeniorUnsecuredNoteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=ne_SeniorNoteSevenSeniorNoteEightandSeniorNoteNineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=ne_UnsecuredRevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=ne_NHILMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Additional Information (Detail) - USD ($)		1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
Debt - Additional Information (Detail) - USD ($)	Oct. 18, 2017	Dec. 31, 2016	Apr. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Jun. 30, 2017	Dec. 28, 2016	Apr. 01, 2016	Mar. 31, 2016
Debt Instrument [Line Items]
Gain on extinguishment of debt, net				$ 0	$ 0	$ 0	$ 11,066,000
Maximum debt to tangible capitalization covenant				60.00%		60.00%
Line of credit facility debt to tangible capitalization ratio				41.00%		41.00%
7.70% Senior Notes due April 2025 [Member]
Debt Instrument [Line Items]
Face value of senior notes				$ 450,000,000		$ 450,000,000
Interest rate on senior notes				7.70%		7.70%
8.70% Senior Notes due April 2045 [Member]
Debt Instrument [Line Items]
Face value of senior notes				$ 400,000,000		$ 400,000,000
Interest rate on senior notes				8.70%		8.70%
4.90% Senior Notes due August 2020 [Member]
Debt Instrument [Line Items]
Face value of senior notes				$ 168,000,000		$ 168,000,000						$ 500,000,000
Interest rate on senior notes				4.90%		4.90%
4.625% Senior Notes due March 2021 [Member]
Debt Instrument [Line Items]
Face value of senior notes				$ 209,000,000		$ 209,000,000						$ 400,000,000
Interest rate on senior notes				4.625%		4.625%						4.625%
4.90% Senior Notes and 4.625% Senior Notes due in August 2020 and March 2021 [Member]
Debt Instrument [Line Items]
Face value of senior notes											$ 36,000,000
Purchase of senior notes											$ 24,000,000
Gain on extinguishment of debt, net			$ 11,100,000
2.50% Senior Notes due March 2017 [Member]
Debt Instrument [Line Items]
Face value of senior notes									$ 300,000,000
Interest rate on senior notes									2.50%
5.75% Senior Notes due March 2018 [Member]
Debt Instrument [Line Items]
Face value of senior notes				$ 250,000,000		$ 250,000,000
Interest rate on senior notes				5.75%		5.75%
3.95% Senior Notes due March 2022 [Member]
Debt Instrument [Line Items]
Face value of senior notes				$ 126,000,000		$ 126,000,000
Interest rate on senior notes				3.95%		3.95%
Maximum [Member] \| Senior Unsecured Note [Member]
Debt Instrument [Line Items]
Interest rate increase (decrease)						0.25%
Senior Notes [Member] \| Senior Unsecured Note [Member]
Debt Instrument [Line Items]
Long-term debt, principal amount		$ 1,000,000,000						$ 1,000,000,000
Senior Notes [Member] \| 7.70% Senior Notes due April 2025 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes				7.70%		7.70%
Senior Notes [Member] \| 7.70% Senior Notes due April 2025 [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Interest rate increase (decrease)	7.95%
Senior Notes [Member] \| 8.70% Senior Notes due April 2045 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes				8.70%		8.70%
Senior Notes [Member] \| 8.70% Senior Notes due April 2045 [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Interest rate increase (decrease)	8.95%
Senior Notes [Member] \| 4.90% Senior Notes due August 2020 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes		4.90%		4.90%		4.90%		4.90%				4.90%
Long-term debt, principal amount		$ 467,800,000						$ 467,800,000
Senior Notes [Member] \| 4.625% Senior Notes due March 2021 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes		4.625%		4.625%		4.625%		4.625%
Long-term debt, principal amount		$ 396,600,000						$ 396,600,000
Senior Notes [Member] \| 2.50% Senior Notes due March 2017 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes		2.50%						2.50%
Senior Notes [Member] \| 5.75% Senior Notes due March 2018 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes				5.75%		5.75%
Senior Notes [Member] \| 3.95% Senior Notes due March 2022 [Member]
Debt Instrument [Line Items]
Interest rate on senior notes		3.95%		3.95%		3.95%		3.95%
Long-term debt, principal amount		$ 400,000,000						$ 400,000,000
Senior Notes [Member] \| Multiple senior notes
Debt Instrument [Line Items]
Purchase of senior notes										$ 762,300,000.0
Repurchase amount										$ 750,000,000
Gain on extinguishment of debt, net								6,700,000
Unsecured Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Senior unsecured revolving credit facility maturity period						5 years
Maximum borrowing capacity under credit facilities				$ 2,400,000,000		$ 2,400,000,000
Unsecured Revolving Credit Facility [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Unused capacity, commitment fee percentage						10.00%
Unsecured Revolving Credit Facility [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Unused capacity, commitment fee percentage						35.00%
Letter of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity under credit facilities				$ 500,000,000		$ 500,000,000
NHIL [Member]
Debt Instrument [Line Items]
Gain on extinguishment of debt, net					$ 0		$ 11,066,000
NHIL [Member] \| Senior Unsecured Note [Member]
Debt Instrument [Line Items]
Face value of senior notes		$ 1,000,000,000						$ 1,000,000,000
Interest rate on senior notes		7.75%						7.75%
Approximate net proceeds from senior notes issuance		$ 967,600,000