Asset Retirement Obligations (Tables)

12 Months Ended

Sep. 30, 2016

Asset Retirement Obligation [Abstract]

Schedule Of Change In Asset Retirement Obligation

The following is a reconciliation of the change in the Company’s asset retirement obligations:

	Year Ended September 30
	2016			2015			2014
	(Thousands)
Balance at Beginning of Year	$	156,805		$	117,713		$	119,511
Liabilities Incurred	2,719			4,433			5,390
Revisions of Estimates	16,721			33,717			(7,886		)
Liabilities Settled	(72,215		)	(6,825		)	(6,955		)
Accretion Expense	8,300			7,767			7,653
Balance at End of Year	$	112,330		$	156,805		$	117,713