Share-Based Payments (Details 2) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Summary of share based compensation expense associated with different programs
Share-based compensation expense included in total costs and expenses	$ 36.6	$ 42.8	$ 111.0	$ 145.1
Capitalized share-based compensation costs	(1.3)	(0.9)	(3.3)	(2.5)
Share-based compensation expense included in total costs and expenses	35.3	41.9	107.7	142.6
Stock Options [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense included in total costs and expenses	1.8	3.0	4.5	23.1
Market stock units [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense included in total costs and expenses	3.5	2.3	11.2	7.8
Time Vested Restricted Stock Units [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense included in total costs and expenses	22.0	30.8	68.2	96.5
Performance vested restricted stock units settled in shares [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense included in total costs and expenses	0.2	0.7	0.9	4.4
Cash settled performance shares [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense included in total costs and expenses	6.2	2.7	21.7	8.0
Employee Stock Purchase Plan [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense included in total costs and expenses	$ 2.9	$ 3.3	$ 4.5	$ 5.3