Commitments and Contingencies - Litigation (Detail) SFr in Millions, $ in Millions	12 Months Ended
	Jan. 31, 2014 USD ($)	Jan. 31, 2014 CHF (SFr)	Jul. 31, 2016 USD ($)	Jul. 31, 2016 CHF (SFr)
Loss Contingencies [Line Items]
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			$ 74.0	SFr 73.0
Maximum Damage Claim Sought By Third Party			3,900.0	3,800.0
Tiffany Parties [Member]
Loss Contingencies [Line Items]
Minimum Damage Claim Sought			122.0	120.0
Maximum Damage Claim Sought			$ 550.0	SFr 540.0