CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Consolidated net loss from continuing operations	$ (142.3)	$ (76.5)	$ (299.8)	$ (129.2)
Income (loss) from discontinued operations, net of tax	0.0	(2.1)	0.0	1,066.4
Total	(142.3)	(78.6)	(299.8)	937.2
Other comprehensive income
Foreign currency translation	16.8	6.4	(0.3)	(81.2)
Postretirement adjustments, net of tax of $34.7 and $37.8 in 2021 and $0.4 and $14.3 in 2020	143.0	40.0	345.2	131.2
Total other comprehensive income	159.8	46.4	344.9	50.0
Comprehensive income (loss)	17.5	(32.2)	45.1	987.2
Less comprehensive income (loss) attributable to noncontrolling interests	(0.8)	0.3	0.3	(1.5)
Comprehensive income (loss) attributable to Unisys Corporation	$ 18.3	$ (32.5)	$ 44.8	$ 988.7