Earnings per Share (Detail) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Basic Earnings (Loss) Per Common Share
Net income (loss) attributable to Unisys Corporation common shareholders	$ (12.4)	$ 78.6	$ 47.6	$ 26.2
Weighted average shares	43,966	43,246	43,827	43,063
Total	$ (0.28)	$ 1.82	$ 1.09	$ 0.61
Diluted Earnings (Loss) Per Common Share
Net income (loss) attributable to Unisys Corporation common shareholders	(12.4)	78.6	47.6	26.2
Add preferred stock dividends		4.1
Net income (loss) attributable to Unisys Corporation for diluted earnings per share	$ (12.4)	$ 82.7	$ 47.6	$ 26.2
Weighted average shares	43,966	43,246	43,827	43,063
Plus incremental shares from assumed conversions
Employee stock plans		464	446	572
Preferred stock		6,913
Adjusted weighted average shares	43,966	50,623	44,273	43,635
Total	$ (0.28)	$ 1.63	$ 1.08	$ 0.60