v3.26.1
Loans Receivable And Allowance For Credit Losses (Delinquent Loans) (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Sep. 30, 2025
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One $ 1,106,095 $ 1,033,723
Year Two 912,743 560,108
Year Three 422,343 1,067,458
Year Four 730,888 1,215,877
Year Five 1,139,490 1,385,026
Prior Years 3,740,605 2,748,460
Revolving Line of Credit 132,995 117,327
Revolving Line of Credit Converted to Term Loan 7,706 8,021
Total Amortized Cost 8,192,865 8,136,000
Financial Asset, Not Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Total Amortized Cost 8,168,061 8,115,913
Financial Asset, 30 to 89 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Total Amortized Cost 13,959 12,363
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Total Amortized Cost 10,845 7,724
One- to Four-Family Segment [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 195,594 233,573
Year Two 221,515 233,389
Year Three 203,879 601,344
Year Four 548,566 972,071
Year Five 909,767 1,266,835
Prior Years 3,531,358 2,607,234
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 5,610,679 5,914,446
One- to Four-Family Segment [Member] | Originated [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Total Amortized Cost 3,640,236 3,776,443
One- to Four-Family Segment [Member] | Originated [Member] | Financial Asset, Not Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 195,594 233,573
Year Two 221,293 232,879
Year Three 203,230 298,045
Year Four 271,352 530,487
Year Five 497,164 740,699
Prior Years 2,240,591 1,730,689
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 3,629,224 3,766,372
One- to Four-Family Segment [Member] | Originated [Member] | Financial Asset, 30 to 89 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 0 0
Year Three 0 66
Year Four 380 908
Year Five 765 473
Prior Years 5,897 5,873
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 7,042 7,320
One- to Four-Family Segment [Member] | Originated [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 222 0
Year Three 154 0
Year Four 538 0
Year Five 18 107
Prior Years 3,038 2,644
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 3,970 2,751
One- to Four-Family Segment [Member] | Correspondent Purchased [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Total Amortized Cost 1,864,904 2,023,397
One- to Four-Family Segment [Member] | Correspondent Purchased [Member] | Financial Asset, Not Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 0 510
Year Three 495 302,960
Year Four 275,333 440,138
Year Five 411,820 525,556
Prior Years 1,171,795 749,725
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 1,859,443 2,018,889
One- to Four-Family Segment [Member] | Correspondent Purchased [Member] | Financial Asset, 30 to 89 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 0 0
Year Three 0 273
Year Four 252 161
Year Five 0 0
Prior Years 1,760 2,664
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 2,012 3,098
One- to Four-Family Segment [Member] | Correspondent Purchased [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 0 0
Year Three 0 0
Year Four 711 377
Year Five 0 0
Prior Years 2,738 1,033
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 3,449 1,410
One- to Four-Family Segment [Member] | Bulk Purchased [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Total Amortized Cost 105,539 114,606
One- to Four-Family Segment [Member] | Bulk Purchased [Member] | Financial Asset, Not Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 0 0
Year Three 0 0
Year Four 0 0
Year Five 0 0
Prior Years 105,039 114,315
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 105,039 114,315
One- to Four-Family Segment [Member] | Bulk Purchased [Member] | Financial Asset, 30 to 89 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 0 0
Year Three 0 0
Year Four 0 0
Year Five 0 0
Prior Years 215 156
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 215 156
One- to Four-Family Segment [Member] | Bulk Purchased [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 0 0
Year Three 0 0
Year Four 0 0
Year Five 0 0
Prior Years 285 135
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 285 135
Commercial Segment [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 904,280 790,804
Year Two 684,638 319,284
Year Three 213,108 461,181
Year Four 178,703 239,182
Year Five 226,070 116,952
Prior Years 206,535 139,000
Revolving Line of Credit 50,873 41,536
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 2,464,207 2,107,939
Commercial Segment [Member] | Commercial Real Estate [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Total Amortized Cost 2,190,959 1,898,183
Commercial Segment [Member] | Commercial Real Estate [Member] | Financial Asset, Not Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 773,173 687,104
Year Two 642,460 292,556
Year Three 190,994 434,882
Year Four 156,036 223,812
Year Five 213,870 111,227
Prior Years 197,633 134,468
Revolving Line of Credit 11,914 9,775
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 2,186,080 1,893,824
Commercial Segment [Member] | Commercial Real Estate [Member] | Financial Asset, 30 to 89 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 1,329 344
Year Three 37 0
Year Four 0 852
Year Five 0 40
Prior Years 692 0
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 2,058 1,236
Commercial Segment [Member] | Commercial Real Estate [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 471 0
Year Two 0 142
Year Three 89 217
Year Four 0 0
Year Five 99 105
Prior Years 2,014 2,609
Revolving Line of Credit 148 50
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 2,821 3,123
Commercial Segment [Member] | Commercial and Industrial [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Total Amortized Cost 273,248 209,756
Commercial Segment [Member] | Commercial and Industrial [Member] | Financial Asset, Not Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 130,636 103,700
Year Two 39,200 26,100
Year Three 21,903 26,082
Year Four 22,662 14,486
Year Five 12,003 5,580
Prior Years 6,146 1,923
Revolving Line of Credit 38,421 31,642
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 270,971 209,513
Commercial Segment [Member] | Commercial and Industrial [Member] | Financial Asset, 30 to 89 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 1,649 0
Year Three 0 0
Year Four 5 32
Year Five 55 0
Prior Years 50 0
Revolving Line of Credit 374 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 2,133 32
Commercial Segment [Member] | Commercial and Industrial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 0 142
Year Three 85 0
Year Four 0 0
Year Five 43 0
Prior Years 0 0
Revolving Line of Credit 16 69
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 144 211
Consumer Segment [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 6,221 9,346
Year Two 6,590 7,435
Year Three 5,356 4,933
Year Four 3,619 4,624
Year Five 3,653 1,239
Prior Years 2,712 2,226
Revolving Line of Credit 82,122 75,791
Revolving Line of Credit Converted to Term Loan 7,706 8,021
Total Amortized Cost 117,979 113,615
Consumer Segment [Member] | Home Equity [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Total Amortized Cost 110,843 105,179
Consumer Segment [Member] | Home Equity [Member] | Financial Asset, Not Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 4,067 5,709
Year Two 4,602 5,481
Year Three 4,217 3,546
Year Four 2,892 3,755
Year Five 3,013 1,064
Prior Years 2,616 2,171
Revolving Line of Credit 81,362 75,137
Revolving Line of Credit Converted to Term Loan 7,493 7,826
Total Amortized Cost 110,262 104,689
Consumer Segment [Member] | Home Equity [Member] | Financial Asset, 30 to 89 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 0 51
Year Three 0 0
Year Four 0 0
Year Five 47 0
Prior Years 3 0
Revolving Line of Credit 269 198
Revolving Line of Credit Converted to Term Loan 124 195
Total Amortized Cost 443 444
Consumer Segment [Member] | Home Equity [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 0 0
Year Two 0 0
Year Three 0 0
Year Four 0 0
Year Five 0 0
Prior Years 0 6
Revolving Line of Credit 49 40
Revolving Line of Credit Converted to Term Loan 89 0
Total Amortized Cost 138 46
Consumer Segment [Member] | Other [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Total Amortized Cost 7,136 8,436
Consumer Segment [Member] | Other [Member] | Financial Asset, Not Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 2,110 3,615
Year Two 1,977 1,847
Year Three 1,139 1,353
Year Four 689 856
Year Five 592 175
Prior Years 93 49
Revolving Line of Credit 442 416
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 7,042 8,311
Consumer Segment [Member] | Other [Member] | Financial Asset, 30 to 89 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 9 15
Year Two 9 42
Year Three 0 20
Year Four 38 0
Year Five 0 0
Prior Years 0 0
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost 56 77
Consumer Segment [Member] | Other [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]    
Financing Receivable, Credit Quality Indicator [Line Items]    
Year One 35 7
Year Two 2 14
Year Three 0 14
Year Four 0 13
Year Five 1 0
Prior Years 0 0
Revolving Line of Credit 0 0
Revolving Line of Credit Converted to Term Loan 0 0
Total Amortized Cost $ 38 $ 48