Restructuring (2010 Restructuring) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended			12 Months Ended			12 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended					12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2010 Restructuring Plan for 2010 [Member]	Jun. 30, 2012 Restructuring Plan for 2010 [Member]	Dec. 31, 2011 Restructuring Plan for 2010 [Member]	Dec. 31, 2010 Professional Employees [Member] Restructuring Plan for 2010 [Member]	Dec. 31, 2010 Non-Salaried Employees [Member] Restructuring Plan for 2010 [Member]	Jun. 30, 2012 Customer Management [Member]	Jun. 30, 2011 Customer Management [Member]	Jun. 30, 2012 Customer Management [Member]	Jun. 30, 2011 Customer Management [Member]	Dec. 31, 2010 Severance Charge [Member] Restructuring Plan for 2010 [Member]	Dec. 31, 2010 Severance Charge [Member] Customer Management [Member] Restructuring Plan for 2010 [Member]	Dec. 31, 2010 Severance Charge [Member] Corporate [Member] Restructuring Plan for 2010 [Member]	Jun. 30, 2012 Facility Closing [Member]	Dec. 31, 2011 Facility Closing [Member]	Dec. 31, 2010 Facility Closing [Member] Restructuring Plan for 2010 [Member]
Restructuring Charges	$ 7.6	$ 0	$ 7.6	$ 0		$ 28.7					$ 1.2	$ 0	$ 1.2	$ 0	$ 19.4	$ 13.3	$ 6.1			$ 9.3
Employees affected									1,000	1,400
Restructuring liability, ending balance					$ 0.2		$ 0.7	$ 1.0										$ 0.2	$ 0.5