Segment Information - (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019
Summary of Segment Information
Total revenue	$ 995.2	$ 1,078.8	$ 2,796.4		$ 3,257.1
Segment gross profit	284.1	271.4	758.5		796.7
Segment selling and administrative expense	226.0	219.9	629.7		674.3
Segment research, development and engineering expense	30.2	36.8	93.4		109.8
Operating income (loss) / Segment operating profit	23.8	23.2	18.3		6.0
Asset Impairment Charges	(4.1)	0.0	(4.1)		0.0
Restructuring and DN Now transformation expenses	(13.8)	(8.6)	(35.3)		(19.8)
Other income (expense)	(146.2)	(53.4)	(240.6)		(153.2)
Income (loss) from continuing operations before taxes	(122.4)	(30.2)	(222.3)		(147.2)
Eurasia Banking
Summary of Segment Information
Total revenue	364.2	405.2	1,012.4		1,218.0
Americas Banking
Summary of Segment Information
Total revenue	368.5	403.7	1,044.6		1,186.3
Retail
Summary of Segment Information
Total revenue	262.5	269.9	739.4		852.8
Operating Segments [Member]
Summary of Segment Information
Intersegment revenue	37.5	38.5	96.2		148.2
Operating income (loss) / Segment operating profit	116.2	83.8	322.6		231.0
Operating Segments [Member] | Eurasia Banking
Summary of Segment Information
Total revenue	364.2	405.2	1,012.4		1,218.0
Intersegment revenue	32.9	35.4	86.7		137.4
Operating income (loss) / Segment operating profit	49.9	41.5	119.9		114.0
Operating Segments [Member] | Americas Banking
Summary of Segment Information
Total revenue	368.5	403.7	1,044.6		1,186.3
Intersegment revenue	4.6	3.1	9.5		10.8
Operating income (loss) / Segment operating profit	43.4	28.8	153.0		79.8
Operating Segments [Member] | Retail
Summary of Segment Information
Total revenue	262.5	269.9	739.4		852.8
Operating income (loss) / Segment operating profit	22.9	13.5	49.7		37.2
Corporate and Reconciling Items [Member]
Summary of Segment Information
Reconciliation Of Operating Profit Loss From Segments To Consolidated, Amount	(92.4)	(60.6)	(304.3)		(225.0)
Corporate
Summary of Segment Information
Operating income (loss) / Segment operating profit	(26.7)	(17.4)	(71.9)	[1]	(63.5)	[1]
Segment Reconciling Items [Member]
Summary of Segment Information
Restructuring and DN Now transformation expenses	(41.8)	(20.6)	(110.2)		(64.2)
Net non-routine expense	$ (19.8)	$ (22.6)	$ (118.1)		$ (97.3)

[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.