Share-Based Payments (Details 1) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Summary of share based compensation expense associated with different programs [Abstract]
Subtotal	$ 50.4	$ 48.1
Capitalized share-based compensation costs	(3.4)	(2.7)
Share-based compensation expense included in total costs and expenses	47.0	45.4
Market stock units
Summary of share based compensation expense associated with different programs [Abstract]
Share-based compensation expense	6.1	9.6
Time-vested restricted stock units
Summary of share based compensation expense associated with different programs [Abstract]
Share-based compensation expense	36.1	26.9
Cash settled performance shares
Summary of share based compensation expense associated with different programs [Abstract]
Share-based compensation expense	4.3	3.5
Performance units
Summary of share based compensation expense associated with different programs [Abstract]
Share-based compensation expense	(0.8)	4.5
Performance stock units settled in stock
Summary of share based compensation expense associated with different programs [Abstract]
Share-based compensation expense	0.7	0.0
Performance stock units settled in cash
Summary of share based compensation expense associated with different programs [Abstract]
Share-based compensation expense	0.1	0.0
Employee stock purchase plan
Summary of share based compensation expense associated with different programs [Abstract]
Share-based compensation expense	$ 3.9	$ 3.6