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Investment Securities Available for Sale (Schedule of Gross Unrealized Losses on Investment Securities and Fair Value) (Details) - USD ($) $ in Thousands | Sep. 30, 2022 | Dec. 31, 2021
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | $ 3,871,993 | $ 6,596,065
Less than 12 months, gross unrealized losses | (433,377) | (96,227)
12 months or longer, fair value | 5,690,956 | 1,523,383
12 months or longer, gross unrealized losses | (1,255,812) | (43,377)
Total, fair value | 9,562,949 | 8,119,448
Total, gross unrealized losses | (1,689,189) | (139,604)
U.S. Treasury securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 359,580 | 49,648
Less than 12 months, gross unrealized losses | (31,435) | (379)
12 months or longer, fair value | 83,875 | 47,590
12 months or longer, gross unrealized losses | (15,999) | (2,248)
Total, fair value | 443,455 | 97,238
Total, gross unrealized losses | (47,434) | (2,627)
U.S. Government agency securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 48,311 | 21,760
Less than 12 months, gross unrealized losses | (3,842) | (387)
12 months or longer, fair value | 0 | 0
12 months or longer, gross unrealized losses | 0 | 0
Total, fair value | 48,311 | 21,760
Total, gross unrealized losses | (3,842) | (387)
Mortgage-backed securities issued by U.S. Government agencies |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 220,484 | 461,078
Less than 12 months, gross unrealized losses | (12,059) | (5,858)
12 months or longer, fair value | 502,128 | 244,264
12 months or longer, gross unrealized losses | (106,064) | (5,606)
Total, fair value | 722,612 | 705,342
Total, gross unrealized losses | (118,123) | (11,464)
Mortgage-backed securities issued by U.S. Government sponsored enterprises |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 2,371,537 | 5,729,476
Less than 12 months, gross unrealized losses | (331,934) | (82,671)
12 months or longer, fair value | 4,461,403 | 643,758
12 months or longer, gross unrealized losses | (1,009,768) | (19,409)
Total, fair value | 6,832,940 | 6,373,234
Total, gross unrealized losses | (1,341,702) | (102,080)
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 171,343 | 187,431
Less than 12 months, gross unrealized losses | (13,315) | (3,981)
12 months or longer, fair value | 513,165 | 504,238
12 months or longer, gross unrealized losses | (93,487) | (12,745)
Total, fair value | 684,508 | 691,669
Total, gross unrealized losses | (106,802) | (16,726)
Commercial mortgage-backed securities issued by U.S. Government agencies or sponsored enterprises |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 682,610 | 146,672
Less than 12 months, gross unrealized losses | (40,538) | (2,951)
12 months or longer, fair value | 130,385 | 83,533
12 months or longer, gross unrealized losses | (30,494) | (3,369)
Total, fair value | 812,995 | 230,205
Total, gross unrealized losses | (71,032) | $ (6,320)
Corporate debt securities and other debt securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 18,128 |
Less than 12 months, gross unrealized losses | (254) |
12 months or longer, fair value | 0 |
12 months or longer, gross unrealized losses | 0 |
Total, fair value | 18,128 |
Total, gross unrealized losses | $ (254) |

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