Commitments and Contingencies (Litigation and Environmental - Narrative) (Details) BRL in Millions, $ in Millions	1 Months Ended	6 Months Ended
	Sep. 30, 2010 BRL	Mar. 31, 2017 USD ($) site	Mar. 31, 2017 BRL site	Sep. 30, 2016 USD ($)
Alleged Anticompete Litigation [Member]
Loss Contingencies [Line Items]
Civil fines imposed	BRL 179.2	$ 57.0
Provision for litigation		0.0
Maximum of loss contingency range subject to interest		$ 57.0	BRL 179.2
Environmental [Member]
Loss Contingencies [Line Items]
Approximate number of sites on which settlement has not been reached | site		33	33
Accrual for environmental loss contingencies		$ 86.1		$ 81.4
Accrual for environmental loss contingencies, maximum payout period		30 years
Environmental [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Estimate of possible exposure from environmental loss contingencies		$ 86.0
Environmental [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Estimate of possible exposure from environmental loss contingencies		$ 99.0