Earnings (Loss) Per Share (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
Income (loss) used in basic and diluted loss per share
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 income (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)
Denominator
Weighted-average number of common shares used in basic and diluted earnings (loss) per share (1)									77.6	76.7	76.0
Net loss attributable to Diebold Nixdorf, Incorporated
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)
Anti-dilutive shares
Anti-dilutive shares not used in calculating diluted weighted-average shares (shares)									2.4	3.2	4.5
Incremental shares, excluded from dilutive calculation, due to resulting in operating loss									1.2	1.6	0.7