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v3.24.3

Investment Securities - Unrealized Losses and Fair Value of Securities (Details) $ in Thousands | Sep. 30, 2024 USD ($) security | Sep. 30, 2023 USD ($) security
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
Number of debt securities with unrealized loss | security | 209 | 232
Available-for-sale securities |  |
Less than 12 months, unrealized gross losses | $ (429) | $ (4,185)
12 months or more, unrealized gross losses | (54,270) | (122,244)
Total, unrealized gross losses | (54,699) | (126,429)
Less than 12 months, fair value | 239,441 | 243,952
12 months or more, fair value | 1,125,962 | 1,393,013
Total, fair value | 1,365,403 | 1,636,965
Held-to-maturity securities |  |
Less than 12 months, unrealized gross losses | 0 | (15)
12 months or more, unrealized gross losses | (36,839) | (68,383)
Total unrealized gross losses | (36,839) | (68,398)
Less than 12 months, fair value | 0 | 1,424
12 months or more, fair value | 348,573 | 353,764
Total, fair value | 348,573 | 355,188
Less than 12 months, unrealized gross losses | (429) | (4,200)
12 months or more, unrealized gross losses | (91,109) | (190,627)
Total unrealized gross losses | (91,538) | (194,827)
Less than 12 months, fair value | 239,441 | 245,376
12 months or more, fair value | 1,474,535 | 1,746,777
Total fair value | 1,713,976 | 1,992,153
Corporate debt securities |  |
Available-for-sale securities |  |
Less than 12 months, unrealized gross losses | 0 | 0
12 months or more, unrealized gross losses | (10,993) | (23,487)
Total, unrealized gross losses | (10,993) | (23,487)
Less than 12 months, fair value | 0 | 0
12 months or more, fair value | 146,060 | 167,452
Total, fair value | 146,060 | 167,452
Municipal bonds |  |
Available-for-sale securities |  |
Less than 12 months, unrealized gross losses | (15) | 0
12 months or more, unrealized gross losses | (394) | (1,250)
Total, unrealized gross losses | (409) | (1,250)
Less than 12 months, fair value | 19,985 | 0
12 months or more, fair value | 15,088 | 14,302
Total, fair value | 35,073 | 14,302
U.S. government and agency securities |  |
Available-for-sale securities |  |
Less than 12 months, unrealized gross losses | 0 | (13)
12 months or more, unrealized gross losses | 0 | (599)
Total, unrealized gross losses | 0 | (612)
Less than 12 months, fair value | 0 | 14,917
12 months or more, fair value | 0 | 21,795
Total, fair value | 0 | 36,712
Asset-backed securities |  |
Available-for-sale securities |  |
Less than 12 months, unrealized gross losses | (249) | (2,142)
12 months or more, unrealized gross losses | (2,373) | (5,788)
Total, unrealized gross losses | (2,622) | (7,930)
Less than 12 months, fair value | 116,173 | 86,800
12 months or more, fair value | 235,846 | 445,454
Total, fair value | 352,019 | 532,254
Mortgage-backed securities |  |
Available-for-sale securities |  |
Less than 12 months, unrealized gross losses | (165) | (2,030)
12 months or more, unrealized gross losses | (40,510) | (91,120)
Total, unrealized gross losses | (40,675) | (93,150)
Less than 12 months, fair value | 103,283 | 142,235
12 months or more, fair value | 728,968 | 744,010
Total, fair value | $ 832,251 | $ 886,245

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