Document and Entity Information shares in Millions	6 Months Ended
	Jun. 30, 2017 shares
Document and Entity Information [Abstract]
Entity Registrant Name	SERVICENOW, INC.
Trading Symbol	NOW
Entity Central Index Key	0001373715
Document Type	10-Q
Document Period End Date	Jun. 30, 2017
Amendment Flag	false
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	170.7