Derivative Instruments and Hedging Activities (Fair Value Of Outstanding Designated And Undesignated Derivative Assets And Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative assets	$ 7,019	$ 3,649
Other Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	1,667	551
Cash flow derivatives
Derivatives, Fair Value [Line Items]
Derivative assets	94	73
Designated hedge derivatives | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative assets	7,019	3,572
Designated hedge derivatives | Other Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	1,432	551
Designated hedge derivatives | Cash flow derivatives | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative assets	94	73
Designated hedge derivatives | Cash flow derivatives | Other Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	1,432	551
Designated hedge derivatives | Interest rate swaps | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative assets	6,925	3,499
Designated hedge derivatives | Interest rate swaps | Other Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	0	0
Hedge derivatives not designated | Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative assets	0	77
Hedge derivatives not designated | Other Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ 235	$ 0