Condensed Consolidated Statement of Equity (Unaudited) - USD ($) shares in Millions, $ in Millions		Total	Cumulative Effect, Period of Adoption, Adjustment	[1]	Common Stock	Capital in Excess of Par Value	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	[1]	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Beginning balance at Dec. 31, 2020		$ 202.5	$ 0.5		$ 49.5	$ 671.8	$ 407.5	$ 0.5		$ (1,000.0)	$ 73.7
Beginning balance, Shares at Dec. 31, 2020					49.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update	[1]	Accounting Standards Update 2016-13 [Member]
Net income		$ 15.4					12.7				2.7
Other comprehensive income (loss)		(42.8)								(40.7)	(2.1)
Dividends to:
Brink’s common shareholders		(7.4)					(7.4)
Noncontrolling interests		(0.4)									(0.4)
Stock options and awards
Compensation expense		7.6				7.6
Consideration from exercise of stock options						2.3
Other share-based benefit transactions		(4.0)			$ 0.2	(4.2)
Other share-based benefit transactions, shares					0.2
Acquisitions with noncontrolling interests		51.4									51.4
Ending balance at Mar. 31, 2021		$ 225.1			$ 49.7	677.5	413.3			(1,040.7)	125.3
Ending balance, Shares at Mar. 31, 2021					49.7
Stock options and awards
Dividends (dollars per share)		$ 0.15
Beginning balance at Dec. 31, 2020		$ 202.5	$ 0.5		$ 49.5	671.8	407.5	$ 0.5		(1,000.0)	73.7
Beginning balance, Shares at Dec. 31, 2020					49.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		42.3
Other comprehensive income (loss)		6.7								8.5
Ending balance at Jun. 30, 2021		302.6			$ 49.8	688.5	427.2			(991.5)	128.6
Ending balance, Shares at Jun. 30, 2021					49.8
Beginning balance at Mar. 31, 2021		225.1			$ 49.7	677.5	413.3			(1,040.7)	125.3
Beginning balance, Shares at Mar. 31, 2021					49.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		26.9					23.9				3.0
Other comprehensive income (loss)		49.5								49.2	0.3
Dividends to:
Brink’s common shareholders		(10.0)					(10.0)
Noncontrolling interests		(1.1)									(1.1)
Stock options and awards
Compensation expense		11.1				11.1
Other share-based benefit transactions		0.0			$ 0.1	(0.1)
Other share-based benefit transactions, shares					0.1
Acquisitions with noncontrolling interests		1.1									1.1
Ending balance at Jun. 30, 2021		$ 302.6			$ 49.8	688.5	427.2			(991.5)	128.6
Ending balance, Shares at Jun. 30, 2021					49.8
Stock options and awards
Dividends (dollars per share)		$ 0.20
Beginning balance at Dec. 31, 2021		$ 252.6			$ 47.4	670.6	312.9			(907.9)	129.6
Beginning balance, Shares at Dec. 31, 2021					47.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		74.2					71.3				2.9
Other comprehensive income (loss)		49.4								50.9	(1.5)
Dividends to:
Brink’s common shareholders		(9.5)					(9.5)
Noncontrolling interests		(1.2)									(1.2)
Stock options and awards
Compensation expense		7.1				7.1
Consideration from exercise of stock options		2.3
Other share-based benefit transactions		(2.8)			$ 0.2	(3.0)
Other share-based benefit transactions, shares					0.2
Ending balance at Mar. 31, 2022		$ 369.8			$ 47.6	674.7	374.7			(857.0)	129.8
Ending balance, Shares at Mar. 31, 2022					47.6
Stock options and awards
Dividends (dollars per share)		$ 0.20
Beginning balance at Dec. 31, 2021		$ 252.6			$ 47.4	670.6	312.9			(907.9)	129.6
Beginning balance, Shares at Dec. 31, 2021					47.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		112.3
Other comprehensive income (loss)		9.8								16.3
Ending balance at Jun. 30, 2022		366.7			$ 47.2	676.1	408.8			(891.6)	126.2
Ending balance, Shares at Jun. 30, 2022					47.2
Beginning balance at Mar. 31, 2022		369.8			$ 47.6	674.7	374.7			(857.0)	129.8
Beginning balance, Shares at Mar. 31, 2022					47.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		38.1					35.1				3.0
Other comprehensive income (loss)		(39.6)								(34.6)	(5.0)
Shares repurchased		0.0			$ (0.5)	(8.0)	8.5
Stock Repurchased During Period, Shares					(0.5)
Dividends to:
Brink’s common shareholders		(9.4)					(9.4)
Noncontrolling interests		(1.6)									(1.6)
Stock options and awards
Compensation expense		14.9				14.9
Other share-based benefit transactions		(5.5)			$ 0.1	(5.5)	(0.1)
Other share-based benefit transactions, shares					0.1
Ending balance at Jun. 30, 2022		$ 366.7			$ 47.2	$ 676.1	$ 408.8			$ (891.6)	$ 126.2
Ending balance, Shares at Jun. 30, 2022					47.2
Stock options and awards
Dividends (dollars per share)		$ 0.20

[1] Effective January 1, 2021, we adopted the provisions of ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. We recognized a cumulative effect adjustment to January 1, 2021 retained earnings as a result of adopting this standard. See Note 1 for further details.