Revenues - Disaggregation of Revenue (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenues	$ 4,851	$ 4,513	$ 3,997	$ 3,737	$ 3,603	$ 3,392	$ 3,281	$ 3,006	$ 17,098	$ 13,282	$ 10,540
Americas
Disaggregation of Revenue [Line Items]
Total revenues									12,051	9,445	7,621
Europe
Disaggregation of Revenue [Line Items]
Total revenues									3,430	2,553	1,916
Asia Pacific
Disaggregation of Revenue [Line Items]
Total revenues									$ 1,617	$ 1,284	$ 1,003
Untied States | Geographic Concentration Risk | Revenue
Disaggregation of Revenue [Line Items]
Concentration risk percentage									96.00%	96.00%	96.00%
Subscription and support
Disaggregation of Revenue [Line Items]
Total revenues									$ 16,043	$ 12,413	$ 9,766
Sales Cloud
Disaggregation of Revenue [Line Items]
Total revenues									4,598	4,040	3,588
Service Cloud
Disaggregation of Revenue [Line Items]
Total revenues									4,466	3,621	2,883
Salesforce Platform and Other
Disaggregation of Revenue [Line Items]
Total revenues									4,473	2,854	1,913
Salesforce Platform and Other | Tableau Software, Inc.
Disaggregation of Revenue [Line Items]
Total revenues									652
Marketing and Commerce Cloud
Disaggregation of Revenue [Line Items]
Total revenues									$ 2,506	$ 1,898	$ 1,382