Segment information - Revenue And Operating Profits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Revenues	$ 755.8	$ 759.2	$ 2,217.1	$ 2,295.6
Operating Profit (Loss)	50.0	25.3	85.9	23.6
Total reportable segments
Segment Reporting Information [Line Items]
Revenues	734.9	739.9	2,140.3	2,243.6
Operating Profit (Loss)	74.6	57.9	170.1	170.3
Corporate expenses
Segment Reporting Information [Line Items]
General, administrative and other expenses	(12.9)	(15.5)	(46.6)	(58.4)
Foreign currency transaction losses	(0.2)	(5.1)	2.5	(8.8)
Reconciliation of segment policies to GAAP	(0.8)	(0.3)	3.7	5.1
Other items not allocated to segments
Segment Reporting Information [Line Items]
Acquisitions and dispositions, Revenues	0.5	0.0	2.8	0.0
Reorganization and Restructuring	(2.3)	(2.9)	(10.4)	(3.2)
U.S. and Mexican retirement plans	(7.9)	(8.0)	(23.3)	(23.9)
Acquisitions and dispositions, Operating profit	(2.2)	0.0	(14.5)	0.3
Largest 5 Markets | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	479.2	475.3	1,406.4	1,446.8
Operating Profit (Loss)	31.5	25.8	60.5	76.0
Global Markets | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	232.6	242.9	668.9	730.2
Operating Profit (Loss)	42.0	34.1	110.5	99.5
Venezuela
Segment Reporting Information [Line Items]
Foreign currency transaction losses				(18.1)
Venezuela | Other items not allocated to segments
Segment Reporting Information [Line Items]
Revenues	20.4	19.3	74.0	52.0
Operating Profit (Loss)	1.7	(0.8)	4.4	(57.8)
U.S. | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	184.2	182.6	545.5	550.3
Operating Profit (Loss)	2.2	1.4	(1.5)	16.1
France | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	108.9	110.8	321.6	323.9
Operating Profit (Loss)	12.7	13.7	27.3	24.5
Mexico | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	71.0	80.4	223.2	251.2
Operating Profit (Loss)	3.1	3.4	9.4	15.8
Brazil | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	76.4	63.6	203.3	205.1
Operating Profit (Loss)	11.1	3.7	19.7	11.9
Canada | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	38.7	37.9	112.8	116.3
Operating Profit (Loss)	2.4	3.6	5.6	7.7
Latin America | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	90.3	91.7	254.5	273.7
Operating Profit (Loss)	22.9	17.6	61.2	53.3
EMEA | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	99.4	111.5	291.0	339.5
Operating Profit (Loss)	11.5	9.4	28.3	26.7
Asia | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	42.9	39.7	123.4	117.0
Operating Profit (Loss)	7.6	7.1	21.0	19.5
Payment Services | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	23.1	21.7	65.0	66.6
Operating Profit (Loss)	$ 1.1	$ (2.0)	$ (0.9)	$ (5.2)