Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Income tax expense	$ 134.0	$ 142.2	$ 251.4	$ 261.5
Effective tax rate	33.90%	34.60%	33.30%	34.40%