Segment Information (Customer Revenue By Classes Of Similar Products Or Services) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenue from External Customer [Line Items]
Customer revenue	$ 928.4	$ 911.2
Revenues, total	928.4	911.2
Technology [Member]
Revenue from External Customer [Line Items]
Customer revenue	105.4	110.9
Revenues, total	136.6	131.6
Intersegment profit	1.2	0.8
Services [Member]
Revenue from External Customer [Line Items]
Customer revenue	823.0	800.3
Revenues, total	823.8	801.2
Systems Integration And Consulting [Member] | Services [Member]
Revenue from External Customer [Line Items]
Customer revenue	307.6	284.9
Outsourcing [Member] | Services [Member]
Revenue from External Customer [Line Items]
Customer revenue	351.4	351.9
Infrastructure Services [Member] | Services [Member]
Revenue from External Customer [Line Items]
Customer revenue	115.3	110.1
Core Maintenance [Member] | Services [Member]
Revenue from External Customer [Line Items]
Customer revenue	48.7	53.4
Enterprise-Class Software And Servers [Member] | Technology [Member]
Revenue from External Customer [Line Items]
Customer revenue	95.7	99.6
Other Technology [Member] | Technology [Member]
Revenue from External Customer [Line Items]
Customer revenue	$ 9.7	$ 11.3