Leases (Maturities of Operating Lease Liabilities) (Details) $ in Thousands	Jul. 31, 2019 USD ($)
Leases [Abstract]
Remaining 2020	$ 2,013
2021	4,105
2022	4,205
2023	4,233
2024	4,288
Thereafter	31,930
Total lease payments	50,774
Less imputed interest	(11,160)
Total lease liabilities	39,614
Operating lease liabilities, Current	3,954
Operating lease liabilities, Non-current	$ 35,660