Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenues		$ 3,690.9	$ 3,683.2	$ 3,488.9
Costs and expenses:
Cost of revenues		2,877.3	2,832.1	2,703.3
Selling, general and administrative expenses		584.5	604.9	509.2
Total costs and expenses		3,461.8	3,437.0	3,212.5
Other operating income (expense)		(15.6)	(9.4)	(1.7)
Operating profit		213.5	236.8	274.7
Interest expense		(96.5)	(90.6)	(66.7)
Loss on deconsolidation of Venezuela operations		0.0	0.0	(126.7)
Interest and other nonoperating income (expense)		(37.7)	(52.7)	(38.8)
Income from continuing operations before tax		79.3	93.5	42.5
Provision for income taxes		56.6	61.0	70.0
Income (loss) from continuing operations		22.7	32.5	(27.5)
Income (loss) from discontinued operations, net of tax		(0.8)	0.7	0.0
Net income (loss)		21.9	33.2	(27.5)
Less net income attributable to noncontrolling interests		5.9	4.2	5.8
Net income (loss) attributable to Brink’s		16.0	29.0	(33.3)
Amounts attributable to Brink’s:
Continuing operations		16.8	28.3	(33.3)
Discontinued operations		(0.8)	0.7	0.0
Net income (loss) attributable to Brink’s		$ 16.0	$ 29.0	$ (33.3)
Basic:
Continuing operations (in dollars per share)	[1]	$ 0.33	$ 0.56	$ (0.65)
Discontinued operations (in dollars per share)	[1]	(0.02)	0.01	0
Net income (loss) (in dollars per share)	[1]	0.32	0.58	(0.65)
Diluted:
Continuing operations (in dollars per share)	[1]	0.33	0.55	(0.65)
Discontinued operations (in dollars per share)	[1]	(0.02)	0.01	0
Net income (loss) (in dollars per share)	[1]	$ 0.31	$ 0.57	$ (0.65)
Weighted-average shares
Basic (shares)		50.4	50.2	50.9
Diluted (shares)		50.8	51.1	50.9

[1] Amounts may not add due to rounding.