Earnings per Share (Detail) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Basic Earnings (Loss) Per Common Share
Net (loss) income attributable to Unisys Corporation common shareholders	$ 46.6	$ (11.6)	$ 60.0	$ (52.4)
Weighted average shares	43,905	43,106	43,758	42,971
Total	$ 1.06	$ (0.27)	$ 1.37	$ (1.22)
Diluted Earnings (Loss) Per Common Share
Net income (loss) attributable to Unisys Corporation common shareholders	46.6	(11.6)	60.0	(52.4)
Add preferred stock dividends	4.1		8.1
Net income (loss) attributable to Unisys Corporation for diluted earnings per share	$ 50.7	$ (11.6)	$ 68.1	$ (52.4)
Weighted average shares	43,905	43,106	43,758	42,971
Plus incremental shares from assumed conversions
Employee stock plans	426		439
Preferred stock	6,913		6,913
Adjusted weighted average shares	51,244	43,106	51,110	42,971
Total	$ 0.99	$ (0.27)	$ 1.33	$ (1.22)