Repositioning Actions and Supplemental Data (Details) (USD $) In Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Repositioning Actions [Abstract]
Severance				$ 92.8
Real estate lease terminations				15.3
Asset and goodwill write-offs related to disposals and other costs				23.2
Repositioning actions, total		131.3		131.3
Severance payments related to repositioning actions				66.1
Severance liability related to repositioning actions	26.7			26.7
Repositioning actions, non-cash charges				23.2
Operating Expenses [Abstract]
Salary and service costs	2,472.8		2,153.4	4,891.1	4,315.8
Office and general expenses	526.5		472.4	937.4	939.0
Total operating expenses	2,999.3		2,625.8	5,828.5	5,254.8
Changes in Operating Capital [Abstract]
Decrease in accounts receivable				299.5	168.8
Increase in work in progress and other current assets				(115.9)	(255.2)
Decrease in accounts payable				(813.0)	(498.5)
Decrease in customer advances and other current liabilities				(418.1)	(213.0)
Increase in severance liability related to repositioning actions				26.7	0
Change in other assets and liabilities, net				207.6	41.8
Change in operating capital				(813.2)	(756.1)
Income taxes paid				168.5	179.2
Interest paid				72.9	77.8
Repositioning Actions [Member]
Operating Expenses [Abstract]
Salary and service costs				92.8
Office and general expenses				38.5
Total operating expenses				131.3
Remeasurement Gain [Member]
Operating Expenses [Abstract]
Office and general expenses				(123.4)
Total operating expenses				$ (123.4)