Organizational Structure and Nature of Operations - (Narrative) (Detail)	12 Months Ended
	Sep. 30, 2021
Bell Rock Capital, LLC [Member]
Non-controlling ownership percentage	10.00%
Bankers Settlement Services Capital Region, LLC [Member]
Non-controlling ownership percentage	3.39%
Malvern Insurance Associates LLC [Member]
Ownership percentage	100.00%
Delaware Statutory Trusts [Member]
Mortgage backed securities percentage	5.00%
Delaware Statutory Trusts [Member] | Coastal Asset Management Co. [Member]
Mortgage backed securities percentage	95.00%
Joliet 55 LLC [Member]
Ownership percentage	100.00%