Revenue (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Revenue, Major Customer [Line Items]
Total operating revenues	$ 1,341.8	$ 4,058.2
Contract with Customer, Refund Liability	60.9	60.9	$ 60.4
Contract with Customer, Liability, Revenue Recognized		0.0
North America [Member]
Revenue, Major Customer [Line Items]
Total operating revenues	835.5	2,483.8
EMEA [Member]
Revenue, Major Customer [Line Items]
Total operating revenues	442.8	1,369.1
Asia Pacific [Member]
Revenue, Major Customer [Line Items]
Total operating revenues	$ 63.5	$ 205.3