Segment Information - (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Summary of Segment Information
Intersegment revenues		$ 1,150.2	$ 1,105.6	$ 2,178.3	$ 2,169.8
Segment operating profit (loss)		7.3	(126.6)	(17.2)	(150.1)
Restructuring charges		(7.4)	(2.2)	(11.2)	(6.1)
Other expense		(53.2)	(32.3)	(99.8)	(56.3)
Income (loss) from continuing operations before taxes		(45.9)	(158.9)	(117.0)	(206.4)
Eurasia Banking
Summary of Segment Information
Intersegment revenues		430.2	437.5	812.8	872.6
Americas Banking
Summary of Segment Information
Intersegment revenues		419.9	370.6	782.6	704.3
Retail
Summary of Segment Information
Intersegment revenues		300.1	297.5	582.9	592.9
Operating Segments [Member]
Summary of Segment Information
Revenue from Related Parties		52.3	35.3	109.7	71.8
Segment operating profit (loss)		86.9	20.4	147.2	55.1
Operating Segments [Member] | Eurasia Banking
Summary of Segment Information
Intersegment revenues		430.2	437.5	812.8	872.6
Revenue from Related Parties		46.8	31.8	102.0	62.8
Segment operating profit (loss)		38.8	18.2	72.5	37.7
Operating Segments [Member] | Americas Banking
Summary of Segment Information
Intersegment revenues		419.9	370.6	782.6	704.3
Revenue from Related Parties		5.5	3.5	7.7	9.0
Segment operating profit (loss)		32.5	(3.3)	51.0	1.7
Operating Segments [Member] | Retail
Summary of Segment Information
Intersegment revenues		300.1	297.5	582.9	592.9
Segment operating profit (loss)		15.6	5.5	23.7	15.7
Corporate and Reconciling Items [Member]
Summary of Segment Information
Segment operating profit (loss)		(79.6)	(147.0)	(164.4)	(205.2)
Corporate
Summary of Segment Information
Segment operating profit (loss)	[1]	(12.9)	(15.1)	(46.1)	(32.2)
Segment Reconciling Items [Member]
Summary of Segment Information
Restructuring charges		(25.4)	(2.2)	(40.5)	(6.1)
Net non-routine expense		$ (41.3)	$ (129.7)	$ (77.8)	$ (166.9)

[1] Corporate charges not allocated to segments include headquarter-based costs associated with procurement, human resources, compensation and benefits, finance and accounting, global development/engineering, global strategy/mergers and acquisitions, global IT, tax, treasury and legal.