Restructuring and Related Costs (Summary Of Severance Charges On Balance Sheet) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Total severance and related costs	$ 3,479	$ 3,962
Employee Severance
Restructuring Cost and Reserve [Line Items]
Total severance and related costs	3,479	3,962
Employee Severance | Accrued payroll and related costs
Restructuring Cost and Reserve [Line Items]
Total severance and related costs	3,257	3,485
Employee Severance | Other accrued liabilities
Restructuring Cost and Reserve [Line Items]
Total severance and related costs	99	98
Employee Severance | Other long-term liabilities
Restructuring Cost and Reserve [Line Items]
Total severance and related costs	$ 123	$ 379