Loans Receivable and Related Allowance for Loan Losses (8) (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Recorded Investment	$ 11,232		$ 13,260
Performing Financing Receivable [Member]
Recorded Investment	3,243		12,170
Nonperforming Financing Receivable [Member]
Recorded Investment	7,989		1,090
Residential Mortgage [Member]
Recorded Investment	3,500		3,372
Residential Mortgage [Member] | Performing Financing Receivable [Member]
Recorded Investment	2,254		2,282
Residential Mortgage [Member] | Nonperforming Financing Receivable [Member]
Recorded Investment	1,246		1,090
Commercial Real Estate [Member]
Recorded Investment	7,559	$ 9,100	9,707
Commercial Real Estate [Member] | Performing Financing Receivable [Member]
Recorded Investment	816		9,707
Commercial Real Estate [Member] | Nonperforming Financing Receivable [Member]
Recorded Investment	6,743
Consumer - Second Mortgages Receivable [Member]
Recorded Investment	173		181
Consumer - Second Mortgages Receivable [Member] | Performing Financing Receivable [Member]
Recorded Investment	$ 173		$ 181