Other Current Assets & Other Current Liabilities - Other Current Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Other Current Assets and Other Current Liabilities [Abstract]
Warranty accruals	$ 316.0	$ 321.3
Contingencies related to completed contracts	140.3	214.9
Provisions	258.8	223.0
Social security liability	101.5	145.0
Redeemable financial liability	174.2	69.7
Other taxes payable	123.8	204.4
Compensation accrual	81.2	123.5
Liabilities held for sale	14.9	13.7
Current portion of accrued pension and other post-retirement benefits	11.1	10.3
Other accrued liabilities	214.0	362.1
Total other current liabilities	$ 1,435.8	$ 1,687.9