Segment Information (Customer Revenue by Classes of Similar Products or Services) (Details) (USD $) In Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010		Jun. 30, 2011	Jun. 30, 2010
Customer revenue	$ 937.2	$ 1,037.0		$ 1,848.4	$ 2,014.4
Revenues, total	937.2	1,037.0	[1]	1,848.4	2,014.4	[1]
Services [Member] | Systems Integration and Consulting [Member]
Customer revenue	286.0	335.3		570.9	630.5
Services [Member] | Outsourcing [Member]
Customer revenue	369.6	383.0		721.5	751.8
Services [Member] | Infrastructure Services [Member]
Customer revenue	129.9	115.1		240.1	240.7
Services [Member] | Core Maintenance [Member]
Customer revenue	57.2	58.6		110.5	119.5
Technology [Member] | Enterprise-Class Servers [Member]
Customer revenue	79.6	131.6		179.3	234.0
Technology [Member] | Other Technology [Member]
Customer revenue	14.9	13.4		26.1	37.9
Technology [Member]
Customer revenue	94.5	145.0		205.4	271.9
Revenues, total	115.8	179.7		247.4	328.8
Services [Member]
Customer revenue	842.7	892.0		1,643.0	1,742.5
Revenues, total	$ 843.6	$ 893.5		$ 1,644.8	$ 1,744.9

[1] Reclassified for discontinued operations. See note (a).