Summary of Significant Accounting Policies - Schedule of Estimated Useful Lives (Details)	12 Months Ended
	Jan. 31, 2018
Capitalized internal-use software costs
Property, Plant and Equipment [Line Items]
Intangible asset, useful life	3 years
Computers and Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	3 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	7 years
Leasehold Improvements | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	7 years