Segment information - Capital Expenditures, Depreciation, Amortization (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment	$ 39.8	$ 27.4	$ 24.2	$ 20.8	$ 39.9	$ 26.0	$ 20.9	$ 14.3	$ 112.2	$ 101.1	$ 136.1
Depreciation and Amortization by Business Segment									128.0	135.7	156.4
Amortization of intangible assets:									3.6	4.2	5.5
Total	$ 34.1	$ 32.4	$ 32.9	$ 32.2	$ 33.6	$ 33.1	$ 36.5	$ 36.7	131.6	139.9	161.9
Business segments
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									98.2	89.8	114.2
Depreciation and Amortization by Business Segment									115.6	120.5	137.2
Business segments | U.S.
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									19.9	21.7	31.1
Depreciation and Amortization by Business Segment									45.6	47.6	49.8
Business segments | France
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									17.3	16.0	17.9
Depreciation and Amortization by Business Segment									15.4	15.5	19.3
Amortization of intangible assets:									0.2	0.2	0.3
Business segments | Mexico
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									12.6	9.3	13.3
Depreciation and Amortization by Business Segment									11.6	14.4	19.6
Business segments | Brazil
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									8.9	6.2	14.7
Depreciation and Amortization by Business Segment									7.8	7.6	8.8
Amortization of intangible assets:									1.1	1.2	1.4
Business segments | Canada
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									9.5	6.1	6.4
Depreciation and Amortization by Business Segment									9.6	8.1	8.5
Business segments | Latin America
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									13.7	13.5	17.0
Depreciation and Amortization by Business Segment									9.7	10.0	12.2
Amortization of intangible assets:									0.2	0.3	0.3
Business segments | EMEA
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									9.9	11.1	9.4
Depreciation and Amortization by Business Segment									10.8	11.5	13.6
Amortization of intangible assets:									0.4	0.6	1.1
Business segments | Asia
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									5.0	4.2	3.6
Depreciation and Amortization by Business Segment									3.6	3.9	3.2
Amortization of intangible assets:									0.8	0.9	0.9
Business segments | Payment Services
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									1.4	1.7	0.8
Depreciation and Amortization by Business Segment									1.5	1.9	2.2
Amortization of intangible assets:									0.9	1.0	1.5
Corporate items
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									9.0	7.0	16.5
Depreciation and Amortization by Business Segment									10.9	11.3	9.7
Largest 5 Markets | Business segments
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									68.2	59.3	83.4
Depreciation and Amortization by Business Segment									90.0	93.2	106.0
Amortization of intangible assets:									1.3	1.4	1.7
Global Markets | Business segments
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									28.6	28.8	30.0
Depreciation and Amortization by Business Segment									24.1	25.4	29.0
Amortization of intangible assets:									1.4	1.8	2.3
Venezuela | Reconciling items
Segment Reporting Information [Line Items]
Capital Expenditures by Business Segment									5.0	4.3	5.4
Depreciation and Amortization by Business Segment									0.7	3.9	9.5
Reorganization and Restructuring 2016 | Reconciling items
Segment Reporting Information [Line Items]
Depreciation and Amortization by Business Segment									$ 0.8	$ 0.0	$ 0.0