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, 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		40.5			34.7		5.8
Other comprehensive income		34.3				33.2	1.1
Dividends to:
Brink’s common shareholders		(5.0)			(5.0)
Noncontrolling interests		(0.2)					(0.2)
Share-based compensation:
Compensation expense		4.5		4.5
Consideration from exercise of stock options		0.7	$ 0.0	0.7
Consideration from exercise of stock options, Shares			0.0
Other share-based benefit transactions		(8.4)	$ 0.4	(8.8)
Other share-based benefit transactions, shares			0.4
Ending balance at Mar. 31, 2017		421.2	$ 50.4	614.5	605.7	(873.8)	24.4
Ending balance, Shares at Mar. 31, 2017			50.4
Beginning balance at Dec. 31, 2017		338.2	$ 50.5	628.6	564.9	(926.6)	20.8
Beginning balance, Shares at Dec. 31, 2017			50.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		25.5			22.3		3.2
Other comprehensive income		12.2				11.1	1.1
Dividends to:
Brink’s common shareholders		(7.6)			(7.6)
Noncontrolling interests		(0.7)					(0.7)
Share-based compensation:
Compensation expense		6.8		6.8
Other share-based benefit transactions		(10.1)	$ 0.4	(10.5)
Other share-based benefit transactions, shares			0.4
Ending balance at Mar. 31, 2018		366.5	$ 50.9	$ 624.9	582.9	(916.6)	$ 24.4
Ending balance, Shares at Mar. 31, 2018			50.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting principle	[1]	$ 2.2			$ 3.3	$ (1.1)

[1] Effective January 1, 2018, we adopted the provisions of ASU 2014-09, Revenue From Contracts with Customers, ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities, and ASU 2016-16, Intra-Entity Transfers of Assets Other Than Inventory. We recognized a cumulative effect adjustment to January 1, 2018 retained earnings as a result of adopting each of these standards. See Note 1 for further details of the impact of each standard.