Leases - Future minimum lease payments under non-cancellable leases (Details) $ in Thousands	Oct. 31, 2019 USD ($)
Finance lease
2020 (remaining six months)	$ 21,178
2021	40,387
2022	33,600
2023	24,855
2024	15,753
Thereafter	6,471
Total lease payments	142,244
Less imputed interest	25,734
Total	116,510
Operating lease
2020 (remaining six months)	19,376
2021	32,481
2022	23,918
2023	17,591
2024	13,264
Thereafter	23,016
Total lease payments	129,646
Less imputed interest	16,572
Total	$ 113,074