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				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
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		65.3
Other comprehensive income (loss)		(17.7)								(14.6)
Ending balance at Sep. 30, 2021		249.0			$ 49.1	690.7	396.2			(1,014.6)	127.6
Ending balance, Shares at Sep. 30, 2021					49.1
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		23.0					19.0				4.0
Other comprehensive income (loss)		(24.4)								(23.1)	(1.3)
Shares repurchased		(50.0)			$ (0.7)	(9.3)	(40.0)
Stock Repurchased During Period, Shares					(0.7)
Dividends to:
Brink’s common shareholders		(9.9)					(9.9)
Noncontrolling interests		(3.5)									(3.5)
Stock options and awards
Compensation expense		9.2				9.2
Other share-based benefit transactions		2.2				2.3	(0.1)
Capital contributions from noncontrolling interest		0.1									0.1
Acquisitions with noncontrolling interests		(0.3)									(0.3)
Ending balance at Sep. 30, 2021		249.0			$ 49.1	690.7	396.2			(1,014.6)	127.6
Ending balance, Shares at Sep. 30, 2021					49.1
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
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
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		134.9
Other comprehensive income (loss)		(23.3)								(12.8)
Stock options and awards
Acquisitions of noncontrolling interests										0.1
Ending balance at Sep. 30, 2022		319.2			$ 46.7	677.4	399.2			(920.6)	116.5
Ending balance, Shares at Sep. 30, 2022					46.7
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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		22.6					19.2				3.4
Other comprehensive income (loss)		(33.1)								(29.1)	(4.0)
Shares repurchased	[2]	(30.5)			$ (0.5)	(10.7)	(19.3)
Stock Repurchased During Period, Shares	[2]				(0.5)
Dividends to:
Brink’s common shareholders		(9.4)					(9.4)
Noncontrolling interests		(4.1)									(4.1)
Stock options and awards
Compensation expense		14.3				14.3
Other share-based benefit transactions		0.3			$ 0.0	0.4	(0.1)
Other share-based benefit transactions, shares					0.0
Capital contributions from noncontrolling interest		0.1									0.1
Acquisitions of noncontrolling interests		(7.8)				(2.7)				0.1	(5.2)
Acquisitions with noncontrolling interests		(0.1)									(0.1)
Ending balance at Sep. 30, 2022		$ 319.2			$ 46.7	$ 677.4	$ 399.2			$ (920.6)	$ 116.5
Ending balance, Shares at Sep. 30, 2022					46.7

[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.

[2] During the third quarter ended September 30, 2022, we repurchased a total of 501,560 shares of our common stock for an aggregate of $27.3 million in cash. On the last two days of September 2022, our agent broker purchased additional shares of our common stock in the open market. We are obligated to pay $3.2 million to repurchase those shares and, as of September 30, 2022, this obligation has been reported as a current liability and a corresponding reduction to equity in our condensed consolidated financial statements. See Note 12 for further details.