Unearned Revenue and Performance Obligations	3 Months Ended
Unearned Revenue and Performance Obligations	Apr. 30, 2017
Deferred Revenue Disclosure [Abstract]
Unearned Revenue and Performance Obligations	Unearned Revenue and Performance Obligations $361 million and $251 million of subscription services revenue was recognized during the three months ended April 30, 2017 and 2016, respectively, that was included in the unearned revenue balances at the beginning of the respective periods. Professional services revenue recognized in the same periods from unearned revenue balances at the beginning of the respective periods was not material. Transaction Price Allocated to the Remaining Performance Obligations As of April 30, 2017, approximately $4.0 billion of revenue is expected to be recognized from remaining performance obligations for subscription contracts. We expect to recognize revenue on approximately two thirds of these remaining performance obligations over the next 24 months, with the balance recognized thereafter. Revenue from remaining performance obligations for professional services contracts as of April 30, 2017 was not material.

The entire disclosure for deferred revenues at the end of the reporting period, and description and amounts of significant changes that occurred during the reporting period. Deferred revenue is a liability as of the balance sheet date related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.