Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 38.1	$ 26.9	$ 112.3	$ 42.3
Benefit plan adjustments:
Benefit plan actuarial gains	12.7	14.6	23.2	14.4
Benefit plan prior service costs	(1.2)	(0.5)	(2.5)	(1.8)
Total benefit plan adjustments	11.5	14.1	20.7	12.6
Foreign currency translation adjustments	(62.6)	37.9	(30.5)	(8.1)
Unrealized net losses on available-for-sale securities	(0.3)	0.0	(0.7)	0.0
Gains on cash flow hedges	11.8	2.7	25.2	9.9
Other comprehensive income (loss) before tax	(39.6)	54.7	14.7	14.4
Provision for income taxes	0.0	5.2	4.9	7.7
Other comprehensive income (loss)	(39.6)	49.5	9.8	6.7
Comprehensive income (loss)	(1.5)	76.4	122.1	49.0
Less comprehensive income (loss) attributable to noncontrolling interests	(2.0)	3.3	(0.6)	3.9
Comprehensive income (loss) attributable to Brink's	$ 0.5	$ 73.1	$ 122.7	$ 45.1