Supplemental Cash Flow Data (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in Operating Capital [Abstract]
(Increase) decrease in accounts receivable	$ (341.6)	$ (376.5)	$ (1,063.6)
(Increase) decrease in work in process and other current assets	5.4	(89.7)	(79.6)
Increase (decrease) in accounts payable	763.2	741.9	1,443.7
Increase (decrease) in customer advances, taxes payable and other current liabilities	4.8	31.6	243.9
Change in other assets and liabilities, net	(83.3)	(4.5)	15.1
Change in operating capital	348.5	302.8	559.5
Income taxes paid	566.0	570.4	540.1
Interest paid	$ 226.2	$ 216.7	$ 173.9