Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Oct. 26, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Trading Symbol	DNOW
Security Exchange Name	NYSE
Entity Registrant Name	NOW INC.
Entity Central Index Key	0001599617
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		110,439,751
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity File Number	001-36325
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-4191184
Entity Address, Address Line One	7402 North Eldridge Parkway
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77041
City Area Code	281
Local Phone Number	823-4700
Title of 12(b) Security	Common Stock, par value $0.01
Entity Interactive Data Current	Yes
Document Quarterly Report	true
Document Transition Report	false