Share-Based Payments (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Summary of share based compensation expense associated with different programs
Subtotal	$ 45.7	$ 36.6	$ 137.3	$ 111.0
Share-based compensation expense included in total costs and expenses	44.2	35.3	133.3	107.7
Capitalized share-based compensation costs	(1.5)	(1.3)	(4.0)	(3.3)
Stock Options [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense	0.7	1.8	1.6	4.5
Market stock units [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense	5.6	3.5	17.2	11.2
Time-vested restricted stock units [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense	21.4	22.0	69.5	68.2
Performance-vested restricted stock units settled in shares [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense	0	0.2	0.1	0.9
Cash settled performance shares [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense	16.4	6.2	45.1	21.7
Employee stock purchase plan [Member]
Summary of share based compensation expense associated with different programs
Share-based compensation expense	$ 1.6	$ 2.9	$ 3.8	$ 4.5