v3.25.2
Investment Securities (Investment Securities Held at a Continuous Loss) (Details) - USD ($)
$ in Thousands
Jun. 30, 2025
Sep. 30, 2024
Schedule of Available For Sale Securities [Line Items]    
Available-for-sale, continuous unrealized loss position, less than 12 Months $ 52,052 $ 9,393
Available-for-sale, continuous unrealized loss position less than 12 Months, Accumulated Loss 4 9
Available-for-sale, continuous unrealized loss position, 12 months or longer 286,529 330,734
Available-for-sale, continuous unrealized loss position, 12 months or longer, accumulated loss 26,201 28,667
Available-for-sale, continuous unrealized loss position 338,581 340,127
Available-for-sale, continuous unrealized loss position, accumulated loss 26,205 28,676
REMIC's    
Schedule of Available For Sale Securities [Line Items]    
Available-for-sale, continuous unrealized loss position, less than 12 Months 1,941 9,393
Available-for-sale, continuous unrealized loss position less than 12 Months, Accumulated Loss 3 9
Available-for-sale, continuous unrealized loss position, 12 months or longer 281,429 325,660
Available-for-sale, continuous unrealized loss position, 12 months or longer, accumulated loss 26,046 28,472
Available-for-sale, continuous unrealized loss position 283,370 335,053
Available-for-sale, continuous unrealized loss position, accumulated loss 26,049 28,481
Fannie Mae Certificates    
Schedule of Available For Sale Securities [Line Items]    
Available-for-sale, continuous unrealized loss position, less than 12 Months 0 0
Available-for-sale, continuous unrealized loss position less than 12 Months, Accumulated Loss 0 0
Available-for-sale, continuous unrealized loss position, 12 months or longer 99 101
Available-for-sale, continuous unrealized loss position, 12 months or longer, accumulated loss 4 2
Available-for-sale, continuous unrealized loss position 99 101
Available-for-sale, continuous unrealized loss position, accumulated loss 4 2
Freddie Mac Certificates    
Schedule of Available For Sale Securities [Line Items]    
Available-for-sale, continuous unrealized loss position, less than 12 Months 0 0
Available-for-sale, continuous unrealized loss position less than 12 Months, Accumulated Loss 0 0
Available-for-sale, continuous unrealized loss position, 12 months or longer 1,108 1,129
Available-for-sale, continuous unrealized loss position, 12 months or longer, accumulated loss 26 9
Available-for-sale, continuous unrealized loss position 1,108 1,129
Available-for-sale, continuous unrealized loss position, accumulated loss 26 9
U.S. government and agency obligations    
Schedule of Available For Sale Securities [Line Items]    
Available-for-sale, continuous unrealized loss position, less than 12 Months 50,111 0
Available-for-sale, continuous unrealized loss position less than 12 Months, Accumulated Loss 1 0
Available-for-sale, continuous unrealized loss position, 12 months or longer 3,893 3,844
Available-for-sale, continuous unrealized loss position, 12 months or longer, accumulated loss 125 184
Available-for-sale, continuous unrealized loss position 54,004 3,844
Available-for-sale, continuous unrealized loss position, accumulated loss $ 126 $ 184