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Investment Securities Available for Sale (Schedule of Gross Unrealized Losses on Investment Securities and Fair Value) (Details) - USD ($) $ in Thousands | Jun. 30, 2022 | Dec. 31, 2021
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | $ 6,737,582 | $ 6,596,065
Less than 12 months, gross unrealized losses | (706,073) | (96,227)
12 months or longer, fair value | 2,802,602 | 1,523,383
12 months or longer, gross unrealized losses | (418,680) | (43,377)
Total, fair value | 9,540,184 | 8,119,448
Total, gross unrealized losses | (1,124,753) | (139,604)
U.S. Treasury securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 322,983 | 49,648
Less than 12 months, gross unrealized losses | (20,632) | (379)
12 months or longer, fair value | 42,319 | 47,590
12 months or longer, gross unrealized losses | (7,528) | (2,248)
Total, fair value | 365,302 | 97,238
Total, gross unrealized losses | (28,160) | (2,627)
U.S. Government agency securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 50,180 | 21,760
Less than 12 months, gross unrealized losses | (1,973) | (387)
12 months or longer, fair value | 0 | 0
12 months or longer, gross unrealized losses | 0 | 0
Total, fair value | 50,180 | 21,760
Total, gross unrealized losses | (1,973) | (387)
Mortgage-backed securities issued by U.S. Government agencies |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 305,938 | 461,078
Less than 12 months, gross unrealized losses | (36,743) | (5,858)
12 months or longer, fair value | 324,431 | 244,264
12 months or longer, gross unrealized losses | (44,782) | (5,606)
Total, fair value | 630,369 | 705,342
Total, gross unrealized losses | (81,525) | (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 | 5,273,030 | 5,729,476
Less than 12 months, gross unrealized losses | (605,258) | (82,671)
12 months or longer, fair value | 1,893,054 | 643,758
12 months or longer, gross unrealized losses | (296,736) | (19,409)
Total, fair value | 7,166,084 | 6,373,234
Total, gross unrealized losses | (901,994) | (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 | 348,932 | 187,431
Less than 12 months, gross unrealized losses | (26,567) | (3,981)
12 months or longer, fair value | 404,154 | 504,238
12 months or longer, gross unrealized losses | (46,926) | (12,745)
Total, fair value | 753,086 | 691,669
Total, gross unrealized losses | (73,493) | (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 | 418,331 | 146,672
Less than 12 months, gross unrealized losses | (14,730) | (2,951)
12 months or longer, fair value | 138,644 | 83,533
12 months or longer, gross unrealized losses | (22,708) | (3,369)
Total, fair value | 556,975 | 230,205
Total, gross unrealized losses | (37,438) | $ (6,320)
Corporate debt securities and other debt securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Less than 12 months, fair value | 18,188 |
Less than 12 months, gross unrealized losses | (170) |
12 months or longer, fair value | 0 |
12 months or longer, gross unrealized losses | 0 |
Total, fair value | 18,188 |
Total, gross unrealized losses | $ (170) |

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