Commitments and Contingencies Commitments (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 30, 2018	Jan. 31, 2020	Jan. 31, 2019
Loss Contingencies [Line Items]
Recorded Unconditional Purchase Obligation Due in Next Twelve Months		$ 32,000
Charitable Gift
Loss Contingencies [Line Items]
Long-term purchase commitment, amount		5,000
Loss Contingency, Loss in Period	$ 4,503		$ 4,503
Loss Contingency Accrual		2,607	3,200
Loss Contingency, Accrual, Current		691	691
Loss Contingency, Accrual, Noncurrent		1,916	2,509
Selling, General and Administrative Expenses | Charitable Gift
Loss Contingencies [Line Items]
Loss Contingency, Loss in Period			$ 4,503
Loss Contingency Accrual, Payments		$ (2,145)