Consolidated Statements of Income (Loss) (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue	$ 1,384	$ 2,126	$ 4,763	$ 6,198
Cost of revenue	1,245	1,975	4,263	5,729
Gross profit	139	151	500	469
Selling, general and administrative	213	293	733	1,014
Goodwill and indefinite-lived intangible asset impairment			1,378	3,186
Long-lived asset impairment		12	513	2,199
Operating loss	(74)	(154)	(2,124)	(5,930)
Interest and financial costs	(21)	(25)	(65)	(75)
Interest income		4	5	16
Equity loss in unconsolidated affiliates	(11)	(4)	(250)	(6)
Other income (expense), net	(8)	(10)	(19)	(36)
Loss before income taxes	(114)	(189)	(2,453)	(6,031)
Provision (benefit) for income taxes	(61)	60	(264)	(323)
Net loss	(53)	(249)	(2,189)	(5,708)
Net income (loss) attributable to noncontrolling interests	2	(5)	6	2
Net loss attributable to Company	$ (55)	$ (244)	$ (2,195)	$ (5,710)
Net loss attributable to Company per share:
Basic	$ (0.14)	$ (0.64)	$ (5.72)	$ (14.95)
Diluted	$ (0.14)	(0.64)	(5.72)	(14.95)
Cash dividends per share		$ 0.05	$ 0.05	$ 0.15
Weighted average shares outstanding:
Basic	385	382	384	382
Diluted	385	382	384	382

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