Acquisition and Strategic Transaction Transaction Expenses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Business Combinations [Abstract]
Strategic transaction expenses	$ 23.5	$ 15.5	$ 61.3	$ 49.0