Fair Value Measurements - Summary of Fair Value of Financial Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Sep. 30, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	$ 177,359	$ 154,921
Fair Value Measurements [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	177,359	154,921
Fair Value Measurements [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	0	0
Fair Value Measurements [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	0	0
Fair Value Measurements [Member] | Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	13,787	7,310
Fair Value Measurements [Member] | Preferred Stock [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	13,787	7,310
Fair Value Measurements [Member] | Preferred Stock [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	0	0
Fair Value Measurements [Member] | Preferred Stock [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	0	0
Fair Value Measurements [Member] | Common Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	163,569	147,608
Fair Value Measurements [Member] | Common Stock [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	163,569	147,608
Fair Value Measurements [Member] | Common Stock [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	0	0
Fair Value Measurements [Member] | Common Stock [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	0	0
Fair Value Measurements [Member] | Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	3	3
Fair Value Measurements [Member] | Mortgage Backed Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	3	3
Fair Value Measurements [Member] | Mortgage Backed Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	0	0
Fair Value Measurements [Member] | Mortgage Backed Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities Available for Sale at Fair Value	$ 0	$ 0