Geographic Information Summary of Revenues by Geographic Area (Detail) - USD ($) $ in Thousands |
3 Months Ended | ||||
|---|---|---|---|---|---|
Apr. 30, 2017 |
Apr. 30, 2016 |
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| Revenue from External Customer [Line Items] | |||||
| Revenues | $ 479,861 | $ 347,677 | [1] | ||
| United States | |||||
| Revenue from External Customer [Line Items] | |||||
| Revenues | 383,171 | 286,349 | |||
| Other countries | |||||
| Revenue from External Customer [Line Items] | |||||
| Revenues | $ 96,690 | $ 61,328 | |||
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