Leases - Future minimum lease payments under non-cancellable leases (Details) $ in Thousands	Jan. 31, 2020 USD ($)
Finance lease
2020 (remaining three months)	$ 11,056
2021	43,879
2022	37,126
2023	28,257
2024	19,028
Thereafter	11,064
Total lease payments	150,410
Less imputed interest	24,583
Total	125,827
Operating lease
2020 (remaining six months)	10,578
2021	37,389
2022	28,697
2023	22,284
2024	17,652
Thereafter	25,960
Total lease payments	142,560
Less imputed interest	19,093
Total	$ 123,467