Income Taxes (Schedule of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Unrecognized tax benefit — beginning of year	$ 174.1	$ 191.2	$ 174.7	$ 132.4
Additions for current year tax positions	1.2	21.9	4.1
Additions for prior year tax positions	0.0	6.3	5.3
Reductions for prior year tax positions	(9.0)	(5.1)	0.0
Settlements	(1.5)	(1.5)	(0.4)
Reductions due to expirations of statute of limitations	(7.8)	(5.1)	(11.8)
Addition due to acquisition	0.0	0.0	45.1
Unrecognized tax benefit — end of year	$ 174.1	$ 191.2	$ 174.7