Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 15.2	$ 14.0	$ 18.0	$ 28.5
Benefit plan adjustments:
Benefit plan actuarial gains	13.2	9.0	31.8	20.3
Benefit plan prior service costs	(1.3)	(1.2)	(2.4)	(2.5)
Deferred profit sharing	0.0	(0.1)	0.0	(0.1)
Total benefit plan adjustments	11.9	7.9	29.4	17.9
Foreign currency translation adjustments	28.2	9.1	(92.1)	9.7
Losses on cash flow hedges	(2.6)	(10.6)	(17.3)	(18.5)
Other comprehensive income (loss) before tax	37.5	6.4	(80.0)	9.1
Provision (benefit) for income taxes	2.3	(0.7)	2.2	(0.2)
Other comprehensive income (loss)	35.2	7.1	(82.2)	9.3
Comprehensive income (loss)	50.4	21.1	(64.2)	37.8
Less comprehensive income attributable to noncontrolling interests	3.3	1.6	3.9	2.7
Comprehensive income (loss) attributable to Brink's	$ 47.1	$ 19.5	$ (68.1)	$ 35.1