v3.26.1
Investment Securities: Held-to-Maturity Investment Securities by Risk (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Sep. 30, 2025
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity $ 117,587 $ 136,861
U.S. Treasury and U.S. government agency securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 56,844 69,646
U.S. government agencies    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 47,025 48,735
Private label residential    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 13,718 17,376
Municipal securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity   605
Bank issued trust preferred securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity   499
AAA/AA/A    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 113,484 131,441
AAA/AA/A | U.S. Treasury and U.S. government agency securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 56,844 69,646
AAA/AA/A | U.S. government agencies    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 47,025 48,735
AAA/AA/A | Private label residential    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 9,615 12,455
AAA/AA/A | Municipal securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity   605
AAA/AA/A | Bank issued trust preferred securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity   0
BBB/BB/B    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 0 0
BBB/BB/B | U.S. Treasury and U.S. government agency securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 0 0
BBB/BB/B | U.S. government agencies    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 0 0
BBB/BB/B | Private label residential    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 0 0
BBB/BB/B | Municipal securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity   0
BBB/BB/B | Bank issued trust preferred securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity   0
Unrated    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 4,103 5,420
Unrated | U.S. Treasury and U.S. government agency securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 0 0
Unrated | U.S. government agencies    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity 0 0
Unrated | Private label residential    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity $ 4,103 4,921
Unrated | Municipal securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity   0
Unrated | Bank issued trust preferred securities    
Debt Securities, Held-to-Maturity, Credit Quality Indicator [Line Items]    
Total held to maturity   $ 499