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Shareholders' Equity and Other Comprehensive Income (Loss) - Schedule of Changes in Accumulated Other Comprehensive Income (Loss) by Component (Net of Income Taxes) (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward] |  |  |  |
Beginning balance | $ 5,638,642 | $ 5,076,672 | $ 5,266,251 | $ 5,144,148
Total other comprehensive income, net of tax amount | 62,424 | 276,588 | 293,968 | 343,287
Ending balance | 5,839,204 | 5,378,171 | 5,839,204 | 5,378,171
Unrealized losses on investment securities available for sale related to residual tax effects remaining in OCI |  |  | 10,200 | 10,200
Unrealized gain (loss) on cash flow hedges related to residual tax effects remaining in OCI |  |  | 11,600 | 11,600
Total |  |  |  |
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward] |  |  |  |
Beginning balance | (739,221) | (1,050,374) | (970,765) | (1,117,073)
Other comprehensive income (loss) before reclassifications | 37,860 | 233,655 | 216,097 | 32,112
Amounts reclassified from AOCI | 24,564 | 42,933 | 77,871 | 311,175
Total other comprehensive income, net of tax amount | 62,424 | 276,588 | 293,968 | 343,287
Ending balance | (676,797) | (773,786) | (676,797) | (773,786)
Net unamortized holding (losses) gains on AFS investment securities transferred to HTM |  |  |  |
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward] |  |  |  |
Beginning balance | (466,163) | (521,780) | (492,828) | 0
Other comprehensive income (loss) before reclassifications | 0 | 0 | 0 | (537,434)
Amounts reclassified from AOCI | 15,271 | 15,044 | 41,936 | 30,698
Total other comprehensive income, net of tax amount | 15,271 | 15,044 | 41,936 | (506,736)
Ending balance | (450,892) | (506,736) | (450,892) | (506,736)
Net unrealized gains (losses) on investment securities AFS |  |  |  |
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward] |  |  |  |
Beginning balance | (270,842) | (410,553) | (411,413) | (998,259)
Other comprehensive income (loss) before reclassifications | 43,892 | 193,466 | 184,463 | 586,495
Amounts reclassified from AOCI | (1,321) | 0 | (1,321) | 194,677
Total other comprehensive income, net of tax amount | 42,571 | 193,466 | 183,142 | 781,172
Ending balance | (228,271) | (217,087) | (228,271) | (217,087)
Net unrealized gains (losses) on cash flow hedges |  |  |  |
Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward] |  |  |  |
Beginning balance | (2,216) | (118,041) | (66,524) | (118,814)
Other comprehensive income (loss) before reclassifications | (6,032) | 40,189 | 31,634 | (16,949)
Amounts reclassified from AOCI | 10,614 | 27,889 | 37,256 | 85,800
Total other comprehensive income, net of tax amount | 4,582 | 68,078 | 68,890 | 68,851
Ending balance | $ 2,366 | $ (49,963) | $ 2,366 | $ (49,963)

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