Information about Geographic Areas and Products - Total Revenues by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2018	Oct. 31, 2017
Revenues by geography
Total revenues	$ 224,731	$ 177,008	$ 629,887	$ 504,575
North America [Member]
Revenues by geography
Total revenues	126,262	96,942	352,697	274,851
Europe and other [Member]
Revenues by geography
Total revenues	66,589	52,342	185,658	151,736
Asia Pacific [Member]
Revenues by geography
Total revenues	$ 31,880	$ 27,724	$ 91,532	$ 77,988