Repositioning Actions (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Repositioning Actions [Abstract]
Severance								$ 92,800,000
Real estate lease terminations								15,300,000
Asset and goodwill write-offs related to disposals and other costs								23,200,000
Repositioning actions, total								131,300,000
Operating Expenses [Abstract]
Salary and service costs									10,380,700,000	10,250,600,000	9,214,200,000
Office and general expenses									2,034,500,000	1,950,800,000	1,868,100,000
Operating expenses	3,396,500,000	3,019,300,000	3,054,600,000	2,944,800,000	3,365,500,000	3,007,500,000	2,999,300,000	2,829,200,000	12,415,200,000	12,201,400,000	11,082,300,000
Repositioning Actions
Operating Expenses [Abstract]
Salary and service costs										92,800,000
Office and general expenses										38,500,000
Operating expenses										131,300,000
Remeasurement Gain
Operating Expenses [Abstract]
Salary and service costs										0
Office and general expenses										(123,400,000)
Operating expenses										$ (123,400,000)