Income Taxes (Reconciliation of the Beginning and Ending Amounts of Gross Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Taxes
Beginning Balance	$ 20,132	$ 23,526	$ 21,469
Additions to current year tax positions	2,675	2,560	3,588
Reductions to prior year tax positions	(14,458)	(5,753)	(2,292)
Additions to prior year tax positions	15	3,501	761
Lapse of applicable statute of limitations		(3,702)
Ending Balance	$ 8,364	$ 20,132	$ 23,526

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 10B
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-Section 50
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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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- Definition

Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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