Condensed Consolidated Statement of Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss	Attributable to Noncontrolling Interests
Beginning balance at Dec. 31, 2015	$ 330.6	$ 48.9	$ 599.6	$ 561.3	$ (891.9)	$ 12.7
Beginning balance, Shares at Dec. 31, 2015		48.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	28.8			21.7		7.1
Other comprehensive income	34.2				32.7	1.5
Common stock issued (in shares)		0.1
Common stock issued	3.0	$ 0.1	2.9
Dividends to:
Brink’s common shareholders ($0.10 per share)	(14.8)			(14.8)
Noncontrolling interests	(3.4)					(3.4)
Share-based compensation:
Compensation expense	6.7		6.7
Consideration from exercise of stock options	10.9	$ 0.4	10.5
Consideration from exercise of stock options, Shares		0.4
Other share-based benefit transactions	(4.0)	$ 0.5	(4.4)	(0.1)
Other share-based benefit transactions, shares		0.5
Ending balance at Sep. 30, 2016	392.2	$ 49.9	615.3	568.3	(859.2)	17.9
Ending balance, Shares at Sep. 30, 2016		49.9
Beginning balance at Dec. 31, 2016	354.8	$ 50.0	618.1	576.0	(907.0)	17.7
Beginning balance, Shares at Dec. 31, 2016		50.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	75.1			68.8		6.3
Other comprehensive income	68.2				66.8	1.4
Dividends to:
Brink’s common shareholders ($0.10 per share)	(20.1)			(20.1)
Noncontrolling interests	(3.5)					(3.5)
Share-based compensation:
Compensation expense	12.5		12.5
Consideration from exercise of stock options	2.7	$ 0.1	2.6
Consideration from exercise of stock options, Shares		0.1
Other share-based benefit transactions	(9.4)	$ 0.4	(9.7)	(0.1)
Other share-based benefit transactions, shares		0.4
Ending balance at Sep. 30, 2017	$ 480.3	$ 50.5	$ 623.5	$ 624.6	$ (840.2)	$ 21.9
Ending balance, Shares at Sep. 30, 2017		50.5