Property And Equipment, Net (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Property And Equipment, Net [Abstract]
Depreciation expense	$ 64.2	$ 66.9	$ 128.3	$ 136.4
Non-cash capital expenditures			$ 6.1		$ 7.0