Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Consolidated net income (loss)	$ 41.7	$ (29.7)
Other comprehensive income:
Foreign currency translation	(5.1)	31.1
Postretirement adjustments, net of tax of $1.0 in 2018 and $(1.0) in 2017	39.0	22.4
Total other comprehensive income	33.9	53.5
Comprehensive income	75.6	23.8
Less comprehensive income attributable to noncontrolling interests	(2.3)	(3.2)
Comprehensive income attributable to Unisys Corporation	$ 73.3	$ 20.6