Consolidated Statements of Income (Loss) (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Revenue	$ 1,417	$ 1,496	$ 2,666	$ 3,379
Cost of revenue	1,186	1,359	2,279	3,018
Gross profit	231	137	387	361
Selling, general and administrative	219	237	463	520
Goodwill and indefinite-lived intangible asset impairment				1,378
Long-lived asset impairment				513
Operating profit (loss)	12	(100)	(76)	(2,050)
Interest and financial costs	(19)	(22)	(39)	(44)
Interest income	2	2	4	5
Equity loss in unconsolidated affiliates		(6)	(4)	(239)
Other income (expense), net	(16)	(8)	(26)	(11)
Loss before income taxes	(21)	(134)	(141)	(2,339)
Provision (benefit) for income taxes	2	(47)	(4)	(203)
Net loss	(23)	(87)	(137)	(2,136)
Net loss attributable to noncontrolling interests	3	6	4	4
Net loss attributable to Company	$ (26)	$ (93)	$ (141)	$ (2,140)
Net loss attributable to Company per share:
Basic	$ (0.07)	$ (0.24)	$ (0.37)	$ (5.57)
Diluted	$ (0.07)	$ (0.24)	$ (0.37)	(5.57)
Cash dividends per share				$ 0.05
Weighted average shares outstanding:
Basic	386	385	386	384
Diluted	386	385	386	384

Impairment charges recognized during period on goodwill and indefinite-lIved intangible assets.

No definition available.

Name:	nov_GoodwillAndIndefiniteLivedIntangibleAssetImpairment
Namespace Prefix:	nov_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate dividends paid during the period for each share of common stock outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770