Fair Value of Financial Instruments - Financial Assets and Liabilities Carried at Fair Value (Details) - USD ($) $ in Millions	Jan. 31, 2020	Jan. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets, fair value	$ 82.7	$ 106.9
Total financial liabilities, fair value	5.5	27.4
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets, fair value	62.0	99.0
Total financial liabilities, fair value	0.0	0.0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets, fair value	20.7	7.9
Total financial liabilities, fair value	5.5	27.4
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets, fair value	0.0	0.0
Total financial liabilities, fair value	0.0	0.0
Precious metal forward contracts | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.2
Precious metal forward contracts | Level 1 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.0
Precious metal forward contracts | Level 2 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.2
Precious metal forward contracts | Level 3 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.0
Foreign exchange forward contracts | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.5
Foreign exchange forward contracts | Accounts Payable and Accrued Liabilities | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	2.9
Foreign exchange forward contracts | Level 1 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.0
Foreign exchange forward contracts | Level 1 | Accounts Payable and Accrued Liabilities | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.0
Foreign exchange forward contracts | Level 2 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.5
Foreign exchange forward contracts | Level 2 | Accounts Payable and Accrued Liabilities | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	2.9
Foreign exchange forward contracts | Level 3 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.0
Foreign exchange forward contracts | Level 3 | Accounts Payable and Accrued Liabilities | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.0
Cross-currency swaps | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	1.9
Cross-currency swaps | Level 1 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.0
Cross-currency swaps | Level 2 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	1.9
Cross-currency swaps | Level 3 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value	0.0
Time deposits | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	22.7	62.7
Time deposits | Level 1 | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	22.7	62.7
Time deposits | Level 2 | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	0.0	0.0
Time deposits | Level 3 | Short-term Investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	0.0	0.0
Marketable securities | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	39.3	36.3
Marketable securities | Level 1 | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	39.3	36.3
Marketable securities | Level 2 | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	0.0	0.0
Marketable securities | Level 3 | Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial assets, fair value	0.0	0.0
Precious metal forward contracts | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	13.0	5.2
Precious metal forward contracts | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		2.7
Precious metal forward contracts | Level 1 | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	0.0	0.0
Precious metal forward contracts | Level 1 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		0.0
Precious metal forward contracts | Level 2 | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	13.0	5.2
Precious metal forward contracts | Level 2 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		2.7
Precious metal forward contracts | Level 3 | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	0.0	0.0
Precious metal forward contracts | Level 3 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		0.0
Foreign exchange forward contracts | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	2.7	1.8
Foreign exchange forward contracts | Prepaid expenses and other current assets | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	2.1	0.9
Foreign exchange forward contracts | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		2.1
Foreign exchange forward contracts | Accounts Payable and Accrued Liabilities | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		2.7
Foreign exchange forward contracts | Level 1 | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	0.0	0.0
Foreign exchange forward contracts | Level 1 | Prepaid expenses and other current assets | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	0.0	0.0
Foreign exchange forward contracts | Level 1 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		0.0
Foreign exchange forward contracts | Level 1 | Accounts Payable and Accrued Liabilities | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		0.0
Foreign exchange forward contracts | Level 2 | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	2.7	1.8
Foreign exchange forward contracts | Level 2 | Prepaid expenses and other current assets | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	2.1	0.9
Foreign exchange forward contracts | Level 2 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		2.1
Foreign exchange forward contracts | Level 2 | Accounts Payable and Accrued Liabilities | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		2.7
Foreign exchange forward contracts | Level 3 | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	0.0	0.0
Foreign exchange forward contracts | Level 3 | Prepaid expenses and other current assets | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	0.0	0.0
Foreign exchange forward contracts | Level 3 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		0.0
Foreign exchange forward contracts | Level 3 | Accounts Payable and Accrued Liabilities | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		0.0
Cross-currency swaps | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	2.9
Cross-currency swaps | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		19.9
Cross-currency swaps | Level 1 | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	0.0
Cross-currency swaps | Level 1 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		0.0
Cross-currency swaps | Level 2 | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	2.9
Cross-currency swaps | Level 2 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		19.9
Cross-currency swaps | Level 3 | Prepaid expenses and other current assets | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets, fair value	$ 0.0
Cross-currency swaps | Level 3 | Accounts Payable and Accrued Liabilities | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability, fair value		$ 0.0