Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Revenues		$ 1,048.8	$ 826.0	$ 2,026.5	$ 1,698.8
Costs and expenses:
Cost of revenues		819.2	683.9	1,578.0	1,377.3
Selling, general and administrative expenses		155.8	139.6	310.1	287.7
Total costs and expenses		975.0	823.5	1,888.1	1,665.0
Other operating income (expense)		(0.5)	(3.5)	(3.4)	(8.6)
Operating profit (loss)		73.3	(1.0)	135.0	25.2
Interest expense		(28.2)	(23.2)	(55.4)	(43.2)
Interest and other nonoperating income (expense)		4.6	(3.0)	(0.9)	(18.6)
Income (loss) from continuing operations before tax		49.7	(27.2)	78.7	(36.6)
Provision (benefit) for income taxes		22.7	(43.2)	36.3	(55.4)
Income from continuing operations		27.0	16.0	42.4	18.8
Loss from discontinued operations, net of tax		(0.1)	(0.8)	(0.1)	(0.8)
Net income		26.9	15.2	42.3	18.0
Less net income attributable to noncontrolling interests		3.0	2.3	5.7	3.3
Net income attributable to Brink’s		23.9	12.9	36.6	14.7
Amounts attributable to Brink’s
Continuing operations		24.0	13.7	36.7	15.5
Discontinued operations		(0.1)	(0.8)	(0.1)	(0.8)
Net income attributable to Brink’s		$ 23.9	$ 12.9	$ 36.6	$ 14.7
Basic:
Continuing operations (dollars per share)	[1]	$ 0.48	$ 0.27	$ 0.73	$ 0.31
Discontinued operations (dollar per share)	[1]	0	(0.02)	0	(0.02)
Net income (dollars per share)	[1]	0.48	0.25	0.73	0.29
Diluted:
Continuing operations (dollars per share)	[1]	0.47	0.27	0.73	0.30
Discontinued operations (dollar per share)	[1]	0	(0.01)	0	(0.02)
Net income (dollars per share)	[1]	$ 0.47	$ 0.25	$ 0.72	$ 0.29
Weighted-average shares
Basic (shares)		50.0	50.8	49.9	50.7
Diluted (shares)		50.5	51.0	50.5	51.2
Cash dividends paid per common share (dollars per share)		$ 0.20	$ 0.15	$ 0.35	$ 0.30

[1] Amounts may not add due to rounding.