Description of Business and Summary of Significant Accounting Policies - Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Depreciation	$ 285.8	$ 202.3	$ 118.1
Capitalized computer software, amortization expense	$ 134.7	34.6	16.4
Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	2 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	5 years
Building [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	40 years
Capitalized website and internal-use software [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	2 years
Capitalized computer software, costs	$ 97.4	55.7	39.3
Capitalized computer software, amortization expense	51.8	40.7	$ 15.6
Capitalized computer software, unamortized	$ 105.0	$ 59.4