Derivative Instruments and Hedging Activities - Gains and losses recognized (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative instruments and hedging activities
Estimated unrealized net gains (losses) from cash flow hedges which are expected to be reclassified into earnings in the next twelve months	$ 600		$ 600
Foreign currency forwards
Derivative instruments and hedging activities
Gains (losses) recognized in OCI	661	$ (848)	(134)	$ 163
Gains (losses) reclassified into earnings - Effective Portion	$ 94	$ (670)	$ 466	$ (1,468)

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

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- Definition

The estimated net amount of unrealized gains or losses on foreign currency cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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- Definition

Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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