Contingencies (Details) $ in Millions	1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
	Jan. 31, 2015 USD ($)	Sep. 30, 2014 item	Jun. 30, 2016 USD ($) a item	Dec. 31, 1992 entity	Nov. 30, 2012 item
Contingencies
Brazil Governmental assessments			$ 7.5
Environmental litigation with respect to Lowry Landfill site
Contingencies
Approximate number of other companies named in a lawsuit with respect to Lowry Landfill | entity				38
Waste Management litigation
Contingencies
Response cost related to site, minimum before the company may be asked to make payments			$ 319.0
Projects costs to date	$ 140.0
Period before projected completion of project when response cost is expected to exceed minimum amount			3 years
Estimated additional cleanup costs			$ 10.0
Estimated additional site costs for the potentially responsible party (PRP) group			1.0
Environmental litigation with respect to Lower Duwamish site
Contingencies
Number of potentially responsible parties (PRPs) | item					50
Number of additional potentially responsible parties (PRPs) | item		20
Expected future remediation costs			$ 342.0
Expected future remediation of area of river bottom | a			200
Site cleanup costs			$ 100.0
Number of companies whose data is under review | item			30
Number of potentially responsible parties (PRP) groups whose data is under review | item			2
Period over which data is reviewed			2 years