Commitments and Contingencies (Tables)

12 Months Ended

Sep. 30, 2019

Commitments and Contingencies Disclosure [Abstract]

Schedule of Change in Asset Retirement Obligation

The following table summarizes ARO activity:

Asset Retirement Obligations	September 30,
(in thousands)	2019
Balance at September 30, 2018	$	1,809
Accretion expense	55
Revision in estimated cash flows	26
Balance at September 30, 2019	$	1,890