Consolidated Statement of Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	AOCI	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 (loss)	23.6			16.7		6.9
Other comprehensive income (loss)	(18.8)				(19.6)	0.8
Dividends to:
Brink’s common shareholders ($0.60 per share)	(27.7)			(27.7)
Noncontrolling interests	(4.6)					(4.6)
Stock options and awards:
Compensation expense	17.7		17.7
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	(9.5)	$ 0.4	(9.8)	(0.1)
Other share-based benefit transactions (shares)		0.4
Ending Balance at Dec. 31, 2017	338.2	$ 50.5	628.6	564.9	(926.6)	20.8
Ending Balance (shares) at Dec. 31, 2017		50.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(27.5)			(33.3)		5.8
Other comprehensive income (loss)	(16.5)				(15.7)	(0.8)
Stock Repurchased During Period, Value	(93.5)	$ (1.3)	(16.9)	(75.3)
Stock Repurchased During Period, Shares		(1.3)
Dividends to:
Brink’s common shareholders ($0.60 per share)	(30.4)			(30.4)
Noncontrolling interests	(5.2)					(5.2)
Stock options and awards:
Compensation expense	28.2		28.2
Consideration from exercise of stock options	0.8	$ 0.0	0.8
Consideration from exercise of stock options (shares)		0.0
Other share-based benefit transactions	(9.4)	$ 0.5	(9.8)	(0.1)
Other share-based benefit transactions (shares)		0.5
Dispositions of noncontrolling interests	(0.4)					(0.4)
Acquisitions of noncontrolling interests	(21.0)		(2.7)		(9.9)	(8.4)
Acquisitions with noncontrolling interests	1.1					1.1
Ending Balance at Dec. 31, 2018	166.6	$ 49.7	628.2	429.1	(953.3)	12.9
Ending Balance (shares) at Dec. 31, 2018		49.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	33.2			29.0		4.2
Other comprehensive income (loss)	3.9				3.1	0.8
Stock Repurchased During Period, Value	0.0	$ 0.0	(0.5)	0.5
Stock Repurchased During Period, Shares		0.0
Dividends to:
Brink’s common shareholders ($0.60 per share)	(29.9)			(29.9)
Noncontrolling interests	(2.3)					(2.3)
Stock options and awards:
Compensation expense	42.7		42.7
Other share-based benefit transactions	(6.8)	$ 0.4	(7.1)	(0.1)
Other share-based benefit transactions (shares)		0.4
Capital contributions from noncontrolling interest	0.2					0.2
Ending Balance at Dec. 31, 2019	$ 207.6	$ 50.1	$ 663.3	$ 457.4	$ (979.0)	$ 15.8
Ending Balance (shares) at Dec. 31, 2019		50.1