Accrued Liabilities (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 17,013	$ 0	$ 17,013	$ 0
Loss Reserve On Contractual Lease Commitments [Member]
Restructuring Cost and Reserve [Line Items]
Loss reserve, noncurrent portion	$ 3,233		3,233			$ 3,927
Duarte Relocation Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			12,504
Restructuring and Related Cost, Expected Cost Remaining					$ 12,000
Industrial Restructuring Charges
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			$ 4,509