Debt (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Debt Instrument [Line Items]
Short-term borrowings	$ 124.9		$ 47.2
Long-term Debt Types [Abstract]
Total long-term debt	3,294.2		3,355.6
Total Debt	3,419.1		3,402.8
Long-term Debt by Current and Noncurrent [Abstract]
Current liabilities	216.9		129.6
Noncurrent liabilities	3,202.2		3,273.2
Other Disclosures [Abstract]
Long-term revolving credit facilities: Borrowings	6,640.5	$ 5,036.1
Long-term revolving credit facilities: Repayments	6,713.1	$ 4,819.1
Brink's Capital credit facility
Other Disclosures [Abstract]
Long-term revolving credit facilities: Borrowings	5,076.3
Long-term revolving credit facilities: Repayments	5,069.3
Term Loan A | Senior Secured Credit Facility - Amended III
Long-term Debt Types [Abstract]
Long-term Debt	1,352.0		1,377.4
Other Disclosures [Abstract]
Debt issue costs	4.2		5.1
Senior unsecured notes | Six hundred million senior unsecured notes
Long-term Debt Types [Abstract]
Long-term Debt	993.8		992.1
Other Disclosures [Abstract]
Debt issue costs	6.2		7.9
Revolving Credit Facility
Long-term Debt Types [Abstract]
Debt	562.6		646.9
Other Non-US Dollar-denominated Facilities
Long-term Debt Types [Abstract]
Debt	168.8		147.0
Other Non-US Dollar-denominated Facilities | Brink's Capital credit facility
Long-term Debt Types [Abstract]
Debt	113.8		106.8
Financing leases
Long-term Debt Types [Abstract]
Financing leases	217.0		192.2
Short-term borrowings
Debt Instrument [Line Items]
Short-term borrowings	$ 124.9		$ 47.2