Leases - Lease assets and liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2022	Jan. 31, 2021
Assets and Liabilities, Lessee [Abstract]
Operating lease assets	$ 169,595	$ 186,070
Classification of operating lease assets	Operating lease assets
Total lease assets	$ 169,595	186,070
Current operating lease liabilities	$ 42,763	43,560
Classification current operating lease liabilities	Current operating lease liabilities
Noncurrent operating lease liabilities	$ 142,868	161,668
Classification of noncurrent operating liabilities	Noncurrent operating lease liabilities
Total lease liabilities	$ 185,631	$ 205,228