Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Basic loss per common share computation:
Net loss attributable to Unisys Corporation	$ (40.1)	$ (18.7)	$ (114.5)	$ (317.3)
Weighted average shares (in shares)	67,787	67,131	67,623	66,211
Basic loss per common share (in dollars per share)	$ (0.59)	$ (0.28)	$ (1.69)	$ (4.79)
Diluted loss per common share computation:
Net loss attributable to Unisys Corporation	$ (40.1)	$ (18.7)	$ (114.5)	$ (317.3)
Weighted average shares (in shares)	67,787	67,131	67,623	66,211
Plus incremental shares from assumed conversions of employee stock plans (in shares)	0	0	0	0
Adjusted weighted average shares (in shares)	67,787	67,131	67,623	66,211
Diluted loss per common share (in dollars per share)	$ (0.59)	$ (0.28)	$ (1.69)	$ (4.79)
Stock options and restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive weighted average securities (in shares)	339	764	531	857