Commitments and Contingencies - Narrative (Details)	3 Months Ended
	Jul. 31, 2019
Minimum
Lessee, Lease, Description [Line Items]
Remaining term of contract	1 year
Operating lease discount rate	3.70%
Maximum
Lessee, Lease, Description [Line Items]
Remaining term of contract	41 years 1 month 6 days
Operating lease discount rate	6.00%