Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net sales	$ 1,105.9	$ 995.2	$ 890.5	$ 910.7	$ 1,151.6	$ 1,078.8	$ 1,150.2	$ 1,028.1	$ 3,902.3	$ 4,408.7	$ 4,578.6
Gross profit	276.5	284.1	247.6	226.8	270.4	271.4	279.2	246.1	1,035.0	1,067.1	898.8
Net loss	(50.4)	(100.9)	(23.1)	(93.4)	(122.6)	(34.8)	(55.3)	(131.9)	(267.8)	(344.6)	(528.7)
Net (loss) income attributable to noncontrolling interests	0.8	0.5	0.6	(0.6)	0.0	0.9	(5.0)	0.8	1.3	(3.3)	2.7
Net loss attributable to Diebold Nixdorf, Incorporated	$ (51.2)	$ (101.4)	$ (23.7)	$ (92.8)	$ (122.6)	$ (35.7)	$ (50.3)	$ (132.7)	$ (269.1)	$ (341.3)	$ (531.4)
Basic and diluted (loss) per share	$ (0.66)	$ (1.31)	$ (0.31)	$ (1.20)	$ (1.60)	$ (0.46)	$ (0.66)	$ (1.74)	$ (3.47)	$ (4.45)	$ (6.99)
Basic and diluted weighted-average shares outstanding	77.7	77.7	77.6	77.2	76.8	76.8	76.7	76.4	77.6	76.7	76.0