Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 14.5	$ 25.5
Benefit plan adjustments:
Benefit plan actuarial gains	11.3	14.8
Benefit plan prior service costs	(1.3)	(0.8)
Total benefit plan adjustments	10.0	14.0
Foreign currency translation adjustments	0.6	1.0
Gains (losses) on cash flow hedges	(7.9)	0.4
Other comprehensive income before tax	2.7	15.4
Provision for income taxes	0.5	3.2
Other comprehensive income	2.2	12.2
Comprehensive income	16.7	37.7
Less comprehensive income attributable to noncontrolling interests	1.1	4.3
Comprehensive income attributable to Brink's	$ 15.6	$ 33.4