Condensed Consolidated Statement of Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Beginning balance at Dec. 31, 2022	$ 570.2	$ 46.3	$ 684.1	$ 417.2	$ (700.5)	$ 123.1
Beginning balance, Shares at Dec. 31, 2022		46.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	18.3			15.0		3.3
Other comprehensive income (loss)	36.0				35.8	0.2
Shares repurchased	(16.0)	$ (0.2)	(3.8)	(12.0)
Stock Repurchased During Period, Shares		(0.2)
Dividends to:
Brink’s common shareholders	(9.3)			(9.3)
Noncontrolling interests	(0.4)					(0.4)
Stock options and awards
Compensation expense	10.9		10.9
Other share-based benefit transactions	(4.7)	$ 0.3	(4.8)	(0.2)
Other share-based benefit transactions, shares		0.3
Ending balance at Mar. 31, 2023	605.0	$ 46.4	686.4	410.7	(664.7)	126.2
Ending balance, Shares at Mar. 31, 2023		46.4
Beginning balance at Dec. 31, 2023	520.2	$ 44.5	675.9	333.0	(656.0)	122.8
Beginning balance, Shares at Dec. 31, 2023		44.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	52.2			49.3		2.9
Other comprehensive income (loss)	(14.8)				(13.0)	(1.8)
Shares repurchased	(21.0)	$ (0.3)	(2.2)	(18.5)
Stock Repurchased During Period, Shares		(0.3)
Dividends to:
Brink’s common shareholders	(9.8)			(9.8)
Stock options and awards
Compensation expense	9.3		9.3
Other share-based benefit transactions	(16.0)	$ 0.4	(16.4)
Other share-based benefit transactions, shares		0.4
Acquisitions of noncontrolling interests	(0.2)		0.2			(0.4)
Ending balance at Mar. 31, 2024	$ 519.9	$ 44.6	$ 666.8	$ 354.0	$ (669.0)	$ 123.5
Ending balance, Shares at Mar. 31, 2024		44.6