Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenues		$ 977.7	$ 872.8
Costs and expenses:
Cost of revenues		758.8	693.4
Selling, general and administrative expenses		154.3	148.1
Total costs and expenses		913.1	841.5
Other operating income (expense)		(2.9)	(5.1)
Operating profit		61.7	26.2
Interest expense		(27.2)	(20.0)
Interest and other nonoperating income (expense)		(5.5)	(15.6)
Income (loss) from continuing operations before tax		29.0	(9.4)
Provision (benefit) for income taxes		13.6	(12.2)
Income from continuing operations		15.4	2.8
Net income		15.4	2.8
Less net income attributable to noncontrolling interests		2.7	1.0
Net income attributable to Brink’s		$ 12.7	$ 1.8
Basic:
Continuing operations (dollars per share)	[1]	$ 0.26	$ 0.04
Net income (dollars per share)	[1]	0.26	0.03
Diluted:
Continuing operations (dollars per share)	[1]	0.25	0.03
Net income (dollars per share)	[1]	$ 0.25	$ 0.03
Weighted-average shares
Basic (shares)		49.8	50.6
Diluted (shares)		50.5	51.3
Cash dividends paid per common share (dollars per share)		$ 0.15	$ 0.15

[1] Amounts may not add due to rounding.