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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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Share-Based Compensation - Summary of Restricted Stock Shares Granted (Parenthetical) (Details)	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Restricted Stock, Target Awards, 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of Awarded Based on Performance Level Achieved	98.80%
Restricted Stock, Target Awards, 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of Awarded Based on Performance Level Achieved		200.00%
Restricted Stock, Target Awards, 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of Awarded Based on Performance Level Achieved			103.70%
Restricted Stock, Target Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Percentage of Award Based on Level of Performance Attained, Maximum	200.00%
Percentage of Award Based on Level of Performance Attained, Minimum	0.00%
Restricted Stock with Service Condition [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Restricted Stock with Service Condition [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Restricted Stock with Service Condition Assumed in Purchase Accounting [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	1 year
Restricted Stock with Service Condition Assumed in Purchase Accounting [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years