Basis of presentation (Details) $ in Millions		3 Months Ended			9 Months Ended
		Sep. 30, 2017 USD ($) ARS / $ VEF / $	Dec. 31, 2016 USD ($) segment	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) segment ARS / $ VEF / $	Sep. 30, 2016 USD ($)	Jun. 30, 2017 VEF / $	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) VEF / $
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of operating segments | segment			9		3
Cash and cash equivalents		$ 241.8	$ 183.5	$ 191.5	$ 241.8	$ 191.5			$ 181.9
Accumulated other comprehensive losses related to Venezuela		840.2	907.0		840.2
Cumulative Effect of New Accounting Principle in Period of Adoption	[1]							$ 0.2
Cost of revenues		(666.4)		(594.4)	(1,905.6)	(1,779.4)
Selling, general and administrative expenses		(116.6)		(102.2)	(346.5)	(315.9)
Operating Profit		66.4		59.7	185.6	115.4
Interest and other expense		$ (21.2)		$ (9.2)	$ (43.8)	(28.3)
Venezuela
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Remeasurement rate | VEF / $		3,345			3,345		628		199
Rate decrease percent		81.00%			81.00%
Income (loss) attributable to noncontrolling interest					$ 1.0	2.7
Argentina
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Official exchange rate | ARS / $		17.3			17.3
Venezuelan bolívar fuerte | Venezuela
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net remeasurement loss					$ 9.1	4.7
Investment in Venezuela operations		$ 23.6	19.2		23.6
Nonmonetary assets		22.2	17.6		22.2
Net monetary assets		3.6	1.4		3.6
Cash and cash equivalents		6.0	6.8		6.0
Accumulated other comprehensive losses related to Venezuela		113.9	114.7		113.9
Argentine pesos | Argentina
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cash and cash equivalents		38.8			38.8
Venezuela Investment | Venezuela
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net payables to other Brink's affiliates			$ 6.1
Venezuela Investment | Venezuelan bolívar fuerte | Venezuela
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net payables to other Brink's affiliates		$ 2.7			2.7
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption	[1]							0.2
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2016-09, Excess Tax Benefit Component
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Excess tax benefit					$ 6.4
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2016-09, Excess Tax Benefit Component | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption								$ 0.2
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of revenues						24.5
Selling, general and administrative expenses						5.0
Operating Profit						29.5
Interest and other expense						$ 29.5

[1] We elected to early adopt the provisions of ASU 2016-09, Improvements to Employee Share-Based Payment Accounting, in the fourth quarter of 2016 resulting in a cumulative effect adjustment to Retained Earnings for previously unrecognized excess tax benefits. See Note 1 for further discussion of the impacts of this standard.