Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 52.2	$ 18.3
Benefit plan adjustments:
Benefit plan actuarial gains	4.1	3.1
Benefit plan prior service costs	(2.8)	(3.0)
Deferred profit sharing	0.1	0.0
Total benefit plan adjustments	1.4	0.1
Foreign currency translation adjustments	(21.5)	43.4
Gains (losses) on available-for-sale securities	1.1	(1.9)
Gains (losses) on cash flow hedges	10.7	(8.7)
Other comprehensive income (loss) before tax	(8.3)	32.9
Provision (benefit) for income taxes	6.5	(3.1)
Other comprehensive income (loss)	(14.8)	36.0
Comprehensive income	37.4	54.3
Less comprehensive income attributable to noncontrolling interests	1.1	3.5
Comprehensive income attributable to Brink's	$ 36.3	$ 50.8