Commitments and Contingencies - Litigation (Details) SFr in Millions, $ in Millions	12 Months Ended
	Jan. 31, 2018 EUR (€)	Jan. 31, 2014 USD ($)	Jan. 31, 2014 CHF (SFr)	Jan. 31, 2018 USD ($)	Jan. 31, 2018 CHF (SFr)
Loss Contingencies [Line Items]
Litigation Settlement, Amount Awarded to Other Party | €	€ 6,340
Loss Contingency, Damages Paid, Value | SFr			SFr 402.7
Arbitration award expense | $		$ 480.2
Swatch Parties [Member]
Loss Contingencies [Line Items]
Minimum Damage Claim Sought By Third Party				$ 78.0	SFr 73.0
Maximum Damage Claim Sought By Third Party				4,100.0	3,800.0
Tiffany Parties [Member]
Loss Contingencies [Line Items]
Minimum Damage Claim Sought				129.0	120.0
Maximum Damage Claim Sought				$ 578.0	SFr 540.0