Share-Based Payments (Details 1) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Summary of share based compensation expense associated with different programs
Subtotal	$ 28.3	$ 58.9	$ 167.6	$ 193.6
Capitalized share-based compensation costs	(2.8)	(2.3)	(8.4)	(7.5)
Share-based compensation expense included in total costs and expenses	25.5	56.6	159.2	186.1
Market stock units
Summary of share based compensation expense associated with different programs
Share-based compensation expense	7.3	7.1	33.4	30.2
Time-vested restricted stock units
Summary of share based compensation expense associated with different programs
Share-based compensation expense	30.4	28.2	94.1	86.6
Cash settled performance shares
Summary of share based compensation expense associated with different programs
Share-based compensation expense	(9.5)	15.2	17.5	50.6
Performance units
Summary of share based compensation expense associated with different programs
Share-based compensation expense	(2.8)	5.7	11.6	16.0
Employee stock purchase plan
Summary of share based compensation expense associated with different programs
Share-based compensation expense	$ 2.9	$ 2.7	$ 11.0	$ 10.2