Property and Equipment - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, software and equipment depreciation, amortization expense	$ 307.7	$ 272.5	$ 215.3
Capitalization of stock-based compensation	23.1	17.9	$ 15.2
Disposal of property plant and equipment	$ 93.4	$ 48.7