Revenues - Remaining Performance Obligation (Details) - USD ($) $ in Millions	Oct. 31, 2021	Jan. 31, 2021
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Current	$ 18,800	$ 18,000
Noncurrent	17,500	18,100
Total	36,300	$ 36,100
Slack
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total	$ 900
Minimum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-11-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Noncurrent remaining performance obligation, recognition period	13 months
Maximum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-11-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Noncurrent remaining performance obligation, recognition period	36 months