Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Consolidated net loss from continuing operations	$ (13.3)	$ (25.4)	$ (142.5)	$ (51.2)
Income from discontinued operations, net of tax	0.4	16.0	1,066.8	54.8
Total	(12.9)	(9.4)	924.3	3.6
Other comprehensive income
Foreign currency translation	40.1	(51.7)	(41.1)	(99.7)
Postretirement adjustments, net of tax of $(7.8) and $6.4 in 2020 and $8.8 and $11.9 in 2019	8.2	63.4	139.4	182.3
Total other comprehensive income	48.3	11.7	98.3	82.6
Comprehensive income	35.4	2.3	1,022.6	86.2
Less comprehensive income attributable to noncontrolling interests	2.0	2.6	0.5	5.8
Comprehensive income (loss) attributable to Unisys Corporation	$ 33.4	$ (0.3)	$ 1,022.1	$ 80.4