Leases - Maturities of lease liabilities (Details) $ in Thousands	Apr. 30, 2020 USD ($)
Operating
Remaining 2020	$ 2,863
2021	10,450
2022	8,568
2023	7,547
2024	6,517
Thereafter	16,136
Total lease payments	52,081
Less: interest	(4,731)
Present value of lease liabilities	47,350
Finance
Remaining 2020	360
2021	1,445
2022	1,431
2023	1,425
2024	1,434
Thereafter	2,476
Total lease payments	8,571
Less: interest	(3,951)
Present value of lease liabilities	4,620
Total
Remaining 2020	3,223
2021	11,895
2022	9,999
2023	8,972
2024	7,951
Thereafter	18,612
Total lease payments	60,652
Less: interest	(8,682)
Total lease liabilities	$ 51,970