FINANCIAL DERIVATIVES - Schedule of Derivative Instruments in Statement of Financial Position (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Notional Disclosures [Abstract]
Notional Amount	$ 24,896,331	$ 25,779,468
Asset
Fair value, asset	27,789	37,478
Netting adjustments	(462)	(1,236)
(Liability)
Fair value, liability	(77,326)	(117,131)
Netting adjustments	462	1,236
Designated as hedge | Fair value hedges: | Receive fixed non-callable
Notional Disclosures [Abstract]
Notional Amount	7,460,685	9,174,253
Asset
Fair value, asset	174	7,767
(Liability)
Fair value, liability	$ (12,165)	$ (1,081)
Weighted- Average Pay Rate	4.71%	2.50%
Weighted- Average Receive Rate	3.40%	5.47%
Weighted- Average Remaining Term (in years)	1 year 6 months 10 days	9 years 6 months 25 days
Designated as hedge | Fair value hedges: | Pay fixed non-callable
Notional Disclosures [Abstract]
Notional Amount	$ 9,657,181	$ 9,776,685
Asset
Fair value, asset	5,134	2,350
(Liability)
Fair value, liability	$ (97)	$ (20,390)
Weighted- Average Pay Rate	2.67%	5.57%
Weighted- Average Receive Rate	4.56%	2.94%
Weighted- Average Remaining Term (in years)	9 years 1 month 13 days	1 year 9 months 10 days
Designated as hedge | Fair value hedges: | Receive fixed callable
Notional Disclosures [Abstract]
Notional Amount	$ 4,592,077	$ 3,879,827
Asset
Fair value, asset	5,119	7,374
(Liability)
Fair value, liability	$ (65,167)	$ (95,984)
Weighted- Average Pay Rate	4.54%	5.40%
Weighted- Average Receive Rate	3.67%	3.40%
Weighted- Average Remaining Term (in years)	2 years 7 months 24 days	2 years 5 months 23 days
Designated as hedge | Cash flow hedges: | Pay fixed non-callable
Notional Disclosures [Abstract]
Notional Amount	$ 540,000	$ 558,000
Asset
Fair value, asset	16,903	20,234
(Liability)
Fair value, liability	$ (2)	$ (43)
Weighted- Average Pay Rate	1.92%	1.94%
Weighted- Average Receive Rate	4.87%	5.82%
Weighted- Average Remaining Term (in years)	3 years 5 months 4 days	4 years 3 months 18 days
No hedge designation | Receive fixed non-callable
Notional Disclosures [Abstract]
Notional Amount	$ 1,803,328	$ 1,358,396
Asset
Fair value, asset	48	263
(Liability)
Fair value, liability	$ (2)	$ (3)
Weighted- Average Pay Rate	4.52%	5.44%
Weighted- Average Receive Rate	4.43%	4.87%
Weighted- Average Remaining Term (in years)	3 months 18 days	7 months 20 days
No hedge designation | Pay fixed non-callable
Notional Disclosures [Abstract]
Notional Amount	$ 157,776	$ 160,623
Asset
Fair value, asset	819	676
(Liability)
Fair value, liability	$ (1)	$ (29)
Weighted- Average Pay Rate	2.92%	2.92%
Weighted- Average Receive Rate	4.75%	5.64%
Weighted- Average Remaining Term (in years)	3 years 4 months 24 days	4 years 4 months 2 days
No hedge designation | Basis swaps
Notional Disclosures [Abstract]
Notional Amount	$ 655,384	$ 850,384
Asset
Fair value, asset	8	39
(Liability)
Fair value, liability	$ (354)	$ (746)
Weighted- Average Pay Rate	4.69%	5.52%
Weighted- Average Receive Rate	4.52%	5.48%
Weighted- Average Remaining Term (in years)	3 years 9 months 29 days	3 years 9 months 29 days
No hedge designation | Treasury futures
Notional Disclosures [Abstract]
Notional Amount	$ 29,900	$ 21,300
Asset
Fair value, asset	46	11
Netting adjustments	(462)	(1,236)
(Liability)
Fair value, liability	0	(91)
Netting adjustments	$ 462	$ 1,236
Weighted- Average Forward Price (in dollars per share)	$ 108.91	$ 112.51