Earnings Per Common Share (Detail) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Basic Loss Per Common Share
Net loss attributable to Unisys Corporation common shareholders	$ (43.2)	$ (53.5)
Weighted average shares	49,821	46,343
Total	$ (0.87)us-gaap_EarningsPerShareBasic	$ (1.15)us-gaap_EarningsPerShareBasic
Diluted Loss Per Common Share
Net loss attributable to Unisys Corporation common shareholders	$ (43.2)	$ (53.5)
Weighted average shares	49,821	46,343
Plus incremental shares from assumed conversions of employee stock plans	0	0
Adjusted weighted average shares	49,821	46,343
Total	$ (0.87)us-gaap_EarningsPerShareDiluted	$ (1.15)us-gaap_EarningsPerShareDiluted

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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