Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 18.3	$ 74.2
Benefit plan adjustments:
Benefit plan actuarial gains	3.1	10.5
Benefit plan prior service costs	(3.0)	(1.3)
Total benefit plan adjustments	0.1	9.2
Foreign currency translation adjustments	43.4	32.1
Unrealized net losses on available-for-sale securities	(1.9)	(0.4)
Gains (losses) on cash flow hedges	(8.7)	13.4
Other comprehensive income before tax	32.9	54.3
Provision (benefit) for income taxes	(3.1)	4.9
Other comprehensive income	36.0	49.4
Comprehensive income	54.3	123.6
Less comprehensive income attributable to noncontrolling interests	3.5	1.4
Comprehensive income attributable to Brink's	$ 50.8	$ 122.2