Capital Stock (Details) - USD ($)				1 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended
	Apr. 14, 2022	Aug. 06, 2021	Aug. 26, 2020	Nov. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Apr. 30, 2022	Sep. 30, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Nov. 02, 2023	Sep. 21, 2023	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
Shares issued and outstanding (in shares)									44,500,000	46,300,000
Dividend declared (in dollars per share)														$ 0.22
Maximum shares allowed for issuance (in shares)									2,000,000
Par value (in dollars per share)									$ 10
Repurchase shares of Brink's common stock									$ 169,900,000	$ 52,200,000	$ 200,000,000.0
500 Million Share Repurchase Program
Subsequent Event [Line Items]
Stock repurchase program amount													$ 500,000,000
250 Million Share Repurchase Program II
Subsequent Event [Line Items]
Stock repurchase program amount															$ 250,000,000
Stock repurchased and retired during period (in shares)									2,297,955	948,395
Repurchase shares of Brink's common stock									$ 169,900,000	$ 52,200,000
Average price per share (in dollars per share)									$ 73.92	$ 55.01
Stock repurchase program remaining amount									$ 28,000,000
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	655,699		4,041,506		1,096,654
Repurchase shares of Brink's common stock							$ 150,000,000	$ 50,000,000		$ 250,000,000		$ 50,000,000
Average price per share (in dollars per share)							$ 65.53	$ 76.25				$ 45.59
ASR, final price per share (in dollars per share)										$ 61.86
ASR August 2020
Subsequent Event [Line Items]
Stock repurchased and retired during period (in shares)			849,978
Accelerated share repurchases payment			$ 50,000,000
ASR, initial price per share (in dollars per share)			$ 58.83
ASR September 2020
Subsequent Event [Line Items]
Stock repurchased and retired during period (in shares)						246,676
ASR August 2021
Subsequent Event [Line Items]
Stock repurchased and retired during period (in shares)		524,315
Accelerated share repurchases payment		$ 50,000,000
ASR, initial price per share (in dollars per share)		$ 95.36
ASR September 2021
Subsequent Event [Line Items]
Stock repurchased and retired during period (in shares)					131,384
ASR November 2021
Subsequent Event [Line Items]
Stock repurchased and retired during period (in shares)				1,742,160
Accelerated share repurchases payment				$ 150,000,000
ASR, initial price per share (in dollars per share)				$ 86.10
ASR April 2022
Subsequent Event [Line Items]
Stock repurchased and retired during period (in shares)	546,993