Capital Stock (Details) - USD ($)			1 Months Ended	3 Months Ended		9 Months Ended
	Nov. 02, 2023	Apr. 14, 2022	Nov. 30, 2021	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 21, 2023	Jul. 13, 2023	Dec. 31, 2022	Oct. 27, 2021	Feb. 06, 2020
Subsequent Event [Line Items]
Shares of common stock authorized (in shares)				100,000,000.0		100,000,000.0				100,000,000.0
Shares issued and outstanding (in shares)				45,300,000		45,300,000				46,300,000
Dividends declared (in dollars per share)								$ 0.22	$ 0.22
Maximum shares allowed for issuance (in shares)				2,000,000		2,000,000
Par value (in dollars per share)				$ 10		$ 10
Repurchase shares of Brink's common stock						$ 105,700,000	$ 27,300,000
ASR November 2021
Subsequent Event [Line Items]
Stock repurchased and retired during period (in shares)			1,742,160
Accelerated share repurchased payment			$ 150,000,000
ASR April 2022
Subsequent Event [Line Items]
Stock repurchased and retired during period (in shares)		546,993
ASR, final price per share (in dollars per share)		$ 65.53
250 Million Share Repurchase Program II
Subsequent Event [Line Items]
Stock repurchase program amount				$ (92,000,000)		$ (92,000,000)					$ (250,000,000)
Stock repurchased and retired during period (in shares)				1,181,106	501,560	1,453,573
Repurchase shares of Brink's common stock				$ 88,200,000	$ 27,300,000	$ 105,700,000
Average price per share (in dollars per share)						$ 72.72
250 Million Share Repurchase Program
Subsequent Event [Line Items]
Stock repurchase program amount												$ (250,000,000)
Stock repurchased and retired during period (in shares)		2,289,153
500 Million Share Repurchase Program | Subsequent Event
Subsequent Event [Line Items]
Stock repurchase program amount	$ (500,000,000)
Subsequent Event, Date	Nov. 02, 2023