Summary of Significant Accounting Policies - Advertising (Details) - USD ($) $ in Millions	12 Months Ended
Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Accounting Policies [Abstract]
Advertising, marketing, public and media relations costs	$ 378.8	$ 394.1	$ 314.9
Advertising costs as percentage of net sales (percentage)	8.60%	8.90%	7.60%

The total expense recognized in the period for promotion, public relations, and brand or product advertising.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.4)
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

Name:	us-gaap_MarketingAndAdvertisingExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration