Segments - Information of total assets for company's reportable segments (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Jan. 31, 2019	Jul. 31, 2018
Segment Reporting Information [Line Items]
Total assets	$ 2,712,436	$ 2,208,058	$ 2,236,634
Corporate Segment
Segment Reporting Information [Line Items]
Total assets	240,643	182,452	151,018
Operating Segments | Wholesale operations
Segment Reporting Information [Line Items]
Total assets	2,109,198	1,834,610	1,880,348
Operating Segments | Retail
Segment Reporting Information [Line Items]
Total assets	$ 362,595	$ 190,996	$ 205,268