Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Taxes [Abstract]
Current Federal Tax Expense	$ (2,345)	$ (3,092)	$ 762
Deferred Federal Income Tax Expense	38,744	6,384	(97,093)
Current State and Local Tax Expense	1,536	1,432	952
Deferred State and Local Income Tax Expense (Benefit)	216	487	(1,738)
Income Tax Expense (Benefit), Total	$ 38,151	$ 5,211	$ (97,117)