Commitments and Contingencies (Tables)

12 Months Ended

Sep. 30, 2015

Commitments and Contingencies Disclosure [Abstract]

Summary of Asset Retirement Obligations Activity

The following table summarizes asset retirement obligations activity:

Asset Retirement Obligations	September 30,
(in thousands)	2015
Balance at September 30, 2014	$	4,543
Accretion expense	110
Revision in estimated cash flows	(2,879		)
Balance at end of period	$	1,774