INVESTMENT SECURITIES - Schedule of Unrealized Losses on Available-for-Sale Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Unrealized loss position for less than 12 months
Fair Value	$ 4,438,674	$ 2,436,978
Unrealized Loss	(41,374)	(23,476)
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	5,294,521	5,226,775
Unrealized Loss	(299,130)	(281,040)
Government/GSE guaranteed MBS
Unrealized loss position for less than 12 months
Fair Value	1,134,042	799,619
Unrealized Loss	(4,373)	(4,695)
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	2,242,621	2,008,388
Unrealized Loss	(91,716)	(84,539)
U.S. Treasuries
Unrealized loss position for less than 12 months
Fair Value	578,053	29,902
Unrealized Loss	(2,304)	(13)
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	95,452	95,270
Unrealized Loss	(112)	(35)
ABS
Unrealized loss position for less than 12 months
Fair Value	44,586
Unrealized Loss	(414)
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	0
Unrealized Loss	0
AgVantage
Unrealized loss position for less than 12 months
Fair Value	2,681,993	1,607,457
Unrealized Loss	(34,283)	(18,768)
Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Fair Value	2,956,448	3,123,117
Unrealized Loss	$ (207,302)	$ (196,466)

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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