Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 21.1	$ 25.9	$ 75.1	$ 28.8
Benefit plan adjustments:
Benefit plan experience gains	9.6	12.4	32.5	36.7
Benefit plan prior service cost	(0.4)	(0.5)	(1.6)	(1.5)
Deferred profit sharing	0.0	0.0	0.1	0.0
Total benefit plan adjustments	9.2	11.9	31.0	35.2
Foreign currency translation adjustments	16.5	(3.0)	49.4	11.3
Unrealized net gains (losses) on available-for-sale securities	(0.3)	0.0	0.4	0.0
Gains (losses) on cash flow hedges	0.0	0.2	(0.1)	(0.2)
Other comprehensive income before tax	25.4	9.1	80.7	46.3
Provision for income taxes	3.7	4.1	12.5	12.1
Other comprehensive income	21.7	5.0	68.2	34.2
Comprehensive income	42.8	30.9	143.3	63.0
Less comprehensive income attributable to noncontrolling interests	3.3	1.9	7.7	8.6
Comprehensive income attributable to Brink's	$ 39.5	$ 29.0	$ 135.6	$ 54.4