CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Consolidated net loss	$ (427.1)	$ (104.9)	$ (449.8)
Other comprehensive income
Foreign currency translation	67.9	(117.5)	(40.5)
Postretirement adjustments, net of tax of $(32.2) in 2023, $15.2 in 2022 and $64.5 in 2021	181.1	291.7	721.8
Total other comprehensive income	249.0	174.2	681.3
Comprehensive (loss) income	(178.1)	69.3	231.5
Comprehensive (loss) income attributable to noncontrolling interests	(23.1)	(12.8)	4.6
Comprehensive (loss) income attributable to Unisys Corporation	$ (155.0)	$ 82.1	$ 226.9