XML 78 R92.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Income Taxes - Summary of Net Operating Loss Carryforwards (Detail) $ in Millions | Dec. 31, 2019 USD ($)
--- | ---
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | $ 1,213
Tax Effected NOL | 270
Valuation Allowance (VA) | (269)
Tax Effected NOL Net of VA | 1
Federal [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 234
Tax Effected NOL | 49
Valuation Allowance (VA) | (49)
State [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 154
Tax Effected NOL | 9
Valuation Allowance (VA) | (9)
Foreign [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 825
Tax Effected NOL | 212
Valuation Allowance (VA) | (211)
Tax Effected NOL Net of VA | 1
2020 - 2024 Expiration [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 83
2020 - 2024 Expiration [Member] | Federal [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 6
2020 - 2024 Expiration [Member] | State [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 4
2020 - 2024 Expiration [Member] | Foreign [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 73
2025 - 2039 Expiration [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 526
2025 - 2039 Expiration [Member] | Federal [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 30
2025 - 2039 Expiration [Member] | State [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 150
2025 - 2039 Expiration [Member] | Foreign [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 346
Unlimited Expiration [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 604
Unlimited Expiration [Member] | Federal [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | 198
Unlimited Expiration [Member] | Foreign [Member] |
Operating Loss Carryforwards [Line Items] |
Total Net Operating Loss (NOL) | $ 406

X
- Definition Operating loss carryforward tax effected. + References No definition available. + Details
Name: | nov_OperatingLossCarryforwardTaxEffected
Namespace Prefix: | nov_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Operating loss carryforwards net of valuation allowance, tax effected. + References No definition available. + Details
Name: | nov_OperatingLossCarryforwardsNetOfValuationAllowanceTaxEffected
Namespace Prefix: | nov_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319 + Details
Name: | us-gaap_OperatingLossCarryforwards
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- 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_OperatingLossCarryforwardsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The portion of the valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from net operating loss carryforwards for which it is more likely than not that a tax benefit will not be realized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 30 -Paragraph 5 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=109238119&loc=d3e30536-109315 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319 + Details
Name: | us-gaap_OperatingLossCarryforwardsValuationAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_DomesticCountryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_StateAndLocalJurisdictionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_ForeignCountryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxCreditCarryforwardAxis=nov_OperatingLossCarryforwardsExpirationPeriodOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxCreditCarryforwardAxis=nov_OperatingLossCarryforwardsExpirationPeriodTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxCreditCarryforwardAxis=nov_OperatingLossCarryforwardNoExpirationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |