Inventories - Textuals (Details) - USD ($) $ in Millions	Oct. 31, 2019	Jan. 31, 2019	Oct. 31, 2018
Inventory [Line Items]
Inventory held on consignment	$ 11.0	$ 4.9	$ 7.3
Prepaid Expenses and Other Current Assets
Inventory [Line Items]
Inventory returns assets	$ 41.9	$ 42.4	$ 37.5

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_InventoryLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration