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Bank segment - Components of Investment Securities (Details) $ in Thousands | Sep. 30, 2024 USD ($) issue | Dec. 31, 2023 USD ($) issue
--- | --- | ---
Available-for-sale |  |
Amortized cost | $ 1,260,132 |
Available-for-sale investment securities, at fair value | 1,084,083 | $ 1,136,439
Held-to-maturity |  |
Held-to-maturity investment securities, at amortized cost | 1,159,229 | 1,201,314
Held-to-maturity investment securities | 1,086,205 |
American Savings Bank (ASB) |  |
Available-for-sale |  |
Amortized cost | 1,260,132 | 1,341,886
Gross unrealized gains | 31 | 0
Gross unrealized losses | (176,080) | (205,447)
Available-for-sale investment securities, at fair value | $ 1,084,083 | $ 1,136,439
Gross unrealized losses, less than 12 months, number of issues | issue | 0 | 3
Gross unrealized losses, less than 12 months, fair value | $ 0 | $ 1,649
Gross unrealized losses, less than 12 months, amount | $ 0 | $ (22)
Gross unrealized losses, 12 months or longer, number of issues | issue | 117 | 128
Gross unrealized losses, 12 months or longer, fair value | $ 1,067,418 | $ 1,120,432
Gross unrealized losses, 12 months or more, amount | (176,080) | (205,425)
Held-to-maturity |  |
Held-to-maturity investment securities, at amortized cost | 1,159,229 | 1,201,314
Gross unrealized gains | 6,355 | 2,221
Gross unrealized losses | (79,379) | (99,867)
Held-to-maturity investment securities | $ 1,086,205 | $ 1,103,668
Less than 12 months, number of issues | issue | 0 | 37
Less than 12 months, fair value | $ 0 | $ 378,326
Less than 12 months, amount | $ 0 | $ (7,610)
12 months or longer, number of issues | issue | 68 | 46
12 months or longer: fair value | $ 702,883 | $ 484,864
12 months or longer, amount | (79,379) | (92,257)
U.S. Treasury and federal agency obligations | American Savings Bank (ASB) |  |
Available-for-sale |  |
Amortized cost | 7,789 | 12,437
Gross unrealized gains | 0 | 0
Gross unrealized losses | (192) | (427)
Available-for-sale investment securities, at fair value | $ 7,597 | $ 12,010
Gross unrealized losses, less than 12 months, number of issues | issue | 0 | 0
Gross unrealized losses, less than 12 months, fair value | $ 0 | $ 0
Gross unrealized losses, less than 12 months, amount | $ 0 | $ 0
Gross unrealized losses, 12 months or longer, number of issues | issue | 6 | 9
Gross unrealized losses, 12 months or longer, fair value | $ 7,597 | $ 12,010
Gross unrealized losses, 12 months or more, amount | (192) | (427)
Held-to-maturity |  |
Held-to-maturity investment securities, at amortized cost | 59,935 | 59,917
Gross unrealized gains | 0 | 0
Gross unrealized losses | (5,686) | (7,135)
Held-to-maturity investment securities | $ 54,249 | $ 52,782
Less than 12 months, number of issues | issue | 0 | 0
Less than 12 months, fair value | $ 0 | $ 0
Less than 12 months, amount | $ 0 | $ 0
12 months or longer, number of issues | issue | 3 | 3
12 months or longer: fair value | $ 54,249 | $ 52,782
12 months or longer, amount | (5,686) | (7,135)
Mortgage-backed securities | American Savings Bank (ASB) |  |
Available-for-sale |  |
Amortized cost | 1,203,271 | 1,279,852
Gross unrealized gains | 31 | 0
Gross unrealized losses | (174,675) | (202,684)
Available-for-sale investment securities, at fair value | $ 1,028,627 | $ 1,077,168
Gross unrealized losses, less than 12 months, number of issues | issue | 0 | 3
Gross unrealized losses, less than 12 months, fair value | $ 0 | $ 1,649
Gross unrealized losses, less than 12 months, amount | $ 0 | $ (22)
Gross unrealized losses, 12 months or longer, number of issues | issue | 108 | 116
Gross unrealized losses, 12 months or longer, fair value | $ 1,025,897 | $ 1,075,519
Gross unrealized losses, 12 months or more, amount | (174,675) | (202,662)
Held-to-maturity |  |
Held-to-maturity investment securities, at amortized cost | 1,099,294 | 1,141,397
Gross unrealized gains | 6,355 | 2,221
Gross unrealized losses | (73,693) | (92,732)
Held-to-maturity investment securities | $ 1,031,956 | $ 1,050,886
Less than 12 months, number of issues | issue | 0 | 37
Less than 12 months, fair value | $ 0 | $ 378,326
Less than 12 months, amount | $ 0 | $ (7,610)
12 months or longer, number of issues | issue | 65 | 43
12 months or longer: fair value | $ 648,634 | $ 432,082
12 months or longer, amount | (73,693) | (85,122)
Corporate bonds | American Savings Bank (ASB) |  |
Available-for-sale |  |
Amortized cost | 35,137 | 35,239
Gross unrealized gains | 0 | 0
Gross unrealized losses | (1,213) | (2,336)
Available-for-sale investment securities, at fair value | $ 33,924 | $ 32,903
Gross unrealized losses, less than 12 months, number of issues | issue | 0 | 0
Gross unrealized losses, less than 12 months, fair value | $ 0 | $ 0
Gross unrealized losses, less than 12 months, amount | $ 0 | $ 0
Gross unrealized losses, 12 months or longer, number of issues | issue | 3 | 3
Gross unrealized losses, 12 months or longer, fair value | $ 33,924 | $ 32,903
Gross unrealized losses, 12 months or more, amount | (1,213) | (2,336)
Mortgage revenue bonds | American Savings Bank (ASB) |  |
Available-for-sale |  |
Amortized cost | 13,935 | 14,358
Gross unrealized gains | 0 | 0
Gross unrealized losses | 0 | 0
Available-for-sale investment securities, at fair value | $ 13,935 | $ 14,358
Gross unrealized losses, less than 12 months, number of issues | issue | 0 | 0
Gross unrealized losses, less than 12 months, fair value | $ 0 | $ 0
Gross unrealized losses, less than 12 months, amount | $ 0 | $ 0
Gross unrealized losses, 12 months or longer, number of issues | issue | 0 | 0
Gross unrealized losses, 12 months or longer, fair value | $ 0 | $ 0
Gross unrealized losses, 12 months or more, amount | $ 0 | $ 0

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