Cost Classifications (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Costs and Expenses [Abstract]
Depreciation and amortization not included in direct operating expenses	$ 51.7	$ 48.4	$ 100.4	$ 86.3
Depreciation and amortization not included in selling, general and administrative expenses	$ 2.3	$ 2.3	$ 4.7	$ 4.4