- Deferred Commissions (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Accounting Policies [Abstract]
Remaining amortization period	6 years		6 years
Contract Assets
Beginning balance	$ 86,044	$ 113,257	$ 114,973	$ 87,313
Additions	30,074	24,582	48,310	40,003
Recognition of deferred commissions	(24,763)	(19,157)	(44,715)	(35,847)
Ending balance	$ 118,568	$ 91,469	$ 118,568	$ 91,469