Accrued Liabilities (Loss Reserve Activity) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2017	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Restructuring Cost and Reserve [Line Items]
Loss reserve on contractual lease commitments, beginning of period		$ 2,464	$ 9,242	$ 2,464	$ 3,212
Additions			0	8,165	39
Payments			(1,650)	(1,387)	(787)
Loss reserve on contractual lease commitments, end of period			$ 5,270	$ 9,242	$ 2,464
Loss Reserve On Contractual Lease Commitments [Member]
Restructuring Cost and Reserve [Line Items]
Additions		$ 8,165
Non-cash adjustments	$ (2,322)