Acquisitions - Additional Information (Details) € in Millions, $ in Millions						3 Months Ended		6 Months Ended		12 Months Ended
	Nov. 22, 2019 USD ($)	Nov. 22, 2019 AUD ($)	Dec. 03, 2018 USD ($)	Dec. 03, 2018 EUR (€)	Oct. 01, 2018 USD ($) ContingentPayment	Jul. 31, 2020 USD ($)	Jul. 31, 2019 USD ($)	Jul. 31, 2020 USD ($)	Jul. 31, 2019 USD ($)	Jan. 31, 2020 USD ($)
Business Acquisition [Line Items]
Goodwill						$ 0	$ 131,936,000	$ 0	$ 131,936,000	$ 136,366,000
Business acquisition, decrease of liability						$ 0	(13,627,000)	$ 0	(13,627,000)
MGDL Distribution PTY Limited
Business Acquisition [Line Items]
Business acquisition, net of cash acquired	$ 600,000	$ 0.9
Percentage of ownership control	51.00%	51.00%
City Time Distribucion, S.L.U
Business Acquisition [Line Items]
Business acquisition, net of cash acquired			$ 4,800,000	€ 4.2
Percentage of ownership control			51.00%	51.00%
MVMT Watches, Inc.
Business Acquisition [Line Items]
Business acquisition, net of cash acquired					$ 108,400,000
Business acquisition, date of acquisition					Oct. 01, 2018
Business acquisition, purchase price initial payment before tax benefits					$ 100,000,000.0
Business acquisition, number of future contingent payments | ContingentPayment					2
Business acquisition, cash acquired					$ 3,800,000
Goodwill					$ 77,500,000
Amortization of goodwill					15 years
Business acquisition, non-current liability					$ 16,500,000
Business acquisition, non-current liability allocated to purchase price					14,500,000
Business combination, non-current liability allocated to deferred compensation expense					2,000,000.0
Business acquisition, liability							1,900,000		1,900,000	0
Business acquisition, decrease of liability										$ (16,900,000)
Percentage of fair value in excess of carrying value										33.00%
MVMT Watches, Inc. | Other Current Assets
Business Acquisition [Line Items]
Business combination, liability allocated to deferred compensation expense							500,000		500,000	$ 500,000
MVMT Watches, Inc. | Other Non-current Assets
Business Acquisition [Line Items]
Business combination, liability allocated to deferred compensation expense							900,000		900,000	1,000,000.0
MVMT Watches, Inc. | Non-operating Income
Business Acquisition [Line Items]
Business acquisition, decrease of liability							$ 13,600,000		$ 13,600,000	$ (15,400,000)
MVMT Watches, Inc. | Maximum
Business Acquisition [Line Items]
Business acquisition, additional purchase price future contingent payments before tax benefits					$ 100,000,000.0