Accrued Liabilities (Changes in Loss Reserve Activity) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring charges, beginning of period		$ 16,522
Payments		(12,445)	(491)
Non-cash adjustments		(3,570)
Restructuring charges, end of period		507	16,522
Loss Reserve On Contractual Lease Commitments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges, beginning of period		3,931	5,270	9,242
Payments		(932)	(1,339)	(1,650)
Non-cash adjustments	$ 2,322			(2,322)
Restructuring charges, end of period		$ 2,999	$ 3,931	$ 5,270