Commitments and Contingencies (Details) In Millions, unless otherwise specified	6 Months Ended
	Mar. 31, 2014 USD ($)	Mar. 31, 2014 CAD	Sep. 30, 2013 CAD	Mar. 31, 2014 Prior To 1995 [member] USD ($)	Mar. 31, 2014 From 2000 to 2005 [Member] USD ($)
Loss Contingency, Damages Sought, Value		10.0
Damages arising due to alleged environmental contamination of the property and breach of lease			10
Walter Energy tax assessment				34.0	82.2
Walter Energy tax assessment prior to 1995 related to timing	21.0
Amount payable pending completion of an IRS audit	11.6
Multiemployer Plans, Withdrawal Obligation	$ 1.0