Contingencies (Minimum Self Insurance Payments) (Details) $ in Thousands	Jan. 31, 2020 USD ($)
Self Insurance, Future Estimated Payments Due
Estimated self insurance payments due in 2021	$ 300
Estimated self insurance payments due in 2022	375
Estimated self insurance payments due in 2023	375
Estimated self insurance payments due in 2024	375
Estimated self insurance payments due in 2025	375
Estimated self insurance payments due thereafter	0
Estimated self insurance payments, gross	1,800
Discount to net present value	(100)
Estimated self insurance payments, net	$ 1,700