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, 2016 USD ($)	Mar. 31, 2016 BRL Sites	Mar. 31, 2016 USD ($) Sites	Sep. 30, 2015 USD ($)
Environmental [Member]
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies				$ 77.0	$ 80.6
Approximate number of sites on which settlement has not been reached | Sites			37	37
Accrual for environmental loss contingencies, Maximum payout period		30 years
Accrual for environmental loss contingencies, Minimum exposure				$ 77.0
Accrual for environmental loss contingencies, Maximum exposure				91.0
Alleged Anticompete Litigation [Member]
Loss Contingencies [Line Items]
Civil fines imposed	BRL 179.2	$ 50.0
Provision for litigation		$ 0.0
Maximum of loss contingency range subject to interest			BRL 179.2	$ 50.0