Share-Based Payments (Details 2) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Summary of share based compensation expense associated with different programs
Share-based compensation expense included in total costs and expenses	$ 36.1	$ 49.4	$ 74.4	$ 102.3
Capitalized share-based compensation costs	(1.0)	(0.7)	(2.0)	(1.6)
Share-based compensation expense included in total costs and expenses	35.1	48.7	72.4	100.7
Stock Options [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense included in total costs and expenses	1.6	9.3	2.7	20.1
Market stock units [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense included in total costs and expenses	4.3	1.9	7.7	5.5
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	19.1	32.3	46.2	65.8
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	0.3	1.3	0.7	3.7
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	10.7	4.2	15.5	5.2
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	$ 0.1	$ 0.4	$ 1.6	$ 2.0