Stock Compensation - Compensation Costs (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Share-based Payment Arrangement [Abstract]
Share-based compensation costs	$ 9,751	$ 10,784	$ 5,866
Income tax benefits on share-based compensation	$ (1,098)	$ (1,656)	$ (2,053)

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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