Segment information - Revenue And Operating Profits (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Revenues	$ 739.5	$ 760.3	$ 1,461.3	$ 1,536.4
Operating Profit (Loss)	22.1	(14.6)	35.9	(1.7)
Total reportable segments
Segment Reporting Information [Line Items]
Revenues	716.5	748.1	1,405.4	1,503.7
Operating Profit (Loss)	51.3	52.6	95.5	112.4
Corporate expenses
Segment Reporting Information [Line Items]
General, administrative and other expenses	(16.1)	(25.3)	(33.7)	(42.9)
Foreign currency transaction gains (losses)	1.4	1.1	2.7	(3.7)
Reconciliation of segment policies to GAAP	1.3	2.2	4.5	5.4
Other items not allocated to segments
Segment Reporting Information [Line Items]
Acquisitions and dispositions, Revenues	1.5	0.0	2.3	0.0
Reorganization and Restructuring	(2.1)	1.2	(8.1)	(0.3)
U.S. and Mexican retirement plans	(8.1)	(7.6)	(15.4)	(15.9)
Acquisitions and dispositions, Operating profit	(6.5)	0.3	(12.3)	0.3
Largest 5 Markets | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	472.8	483.9	927.2	971.5
Operating Profit (Loss)	15.6	22.1	29.0	50.2
Global Markets | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	222.7	242.1	436.3	487.3
Operating Profit (Loss)	37.7	34.2	68.5	65.4
Venezuela
Segment Reporting Information [Line Items]
Foreign currency transaction gains (losses)				(18.2)
Venezuela | Other items not allocated to segments
Segment Reporting Information [Line Items]
Revenues	21.5	12.2	53.6	32.7
Operating Profit (Loss)	0.9	(39.1)	2.7	(57.0)
U.S. | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	182.5	184.1	361.3	367.7
Operating Profit (Loss)	(1.5)	6.4	(3.7)	14.7
France | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	107.9	107.4	212.7	213.1
Operating Profit (Loss)	10.1	6.7	14.6	10.8
Mexico | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	77.3	85.1	152.2	170.8
Operating Profit (Loss)	3.1	4.5	6.3	12.4
Brazil | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	66.9	67.7	126.9	141.5
Operating Profit (Loss)	2.5	2.1	8.6	8.2
Canada | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	38.2	39.6	74.1	78.4
Operating Profit (Loss)	1.4	2.4	3.2	4.1
Latin America | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	85.0	91.2	164.2	182.0
Operating Profit (Loss)	20.8	19.2	38.3	35.7
EMEA | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	96.2	112.3	191.6	228.0
Operating Profit (Loss)	9.9	9.1	16.8	17.3
Asia | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	41.5	38.6	80.5	77.3
Operating Profit (Loss)	7.0	5.9	13.4	12.4
Payment Services | Total reportable segments
Segment Reporting Information [Line Items]
Revenues	21.0	22.1	41.9	44.9
Operating Profit (Loss)	$ (2.0)	$ (3.7)	$ (2.0)	$ (3.2)