Segments - Information of total assets for company's reportable segments (Details) - USD ($) $ in Thousands	Apr. 30, 2019	Jan. 31, 2019	Apr. 30, 2018
Segment Reporting Information [Line Items]
Total assets	$ 2,446,544	$ 2,208,058	$ 2,040,563
Corporate Segment
Segment Reporting Information [Line Items]
Total assets	256,687	182,452	173,374
Operating Segments | Wholesale operations
Segment Reporting Information [Line Items]
Total assets	1,813,238	1,834,610	1,655,714
Operating Segments | Retail
Segment Reporting Information [Line Items]
Total assets	$ 376,619	$ 190,996	$ 211,475