NOTES PAYABLE - Borrowings (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2026	Dec. 31, 2025
Due within one year:
Outstanding, Amount	$ 12,919,471	$ 11,271,682
Outstanding, Weighted - average rate	3.41%	3.34%
Medium-term notes due in:
Total due after one year	$ 21,860,433
Total principal net of discounts	34,779,904	$ 30,815,880
Hedging adjustments	(85,983)	6,690
Total	$ 34,693,922	30,822,570
Weighted average rate	3.63%
Discount notes
Due within one year:
Outstanding, Amount	$ 2,121,771	$ 2,614,571
Outstanding, Weighted - average rate	3.72%	3.87%
Average Outstanding, Amount	$ 1,963,155	$ 1,854,488
Average Outstanding, Weighted - average rate (as a percent)	3.72%	4.22%
Medium-term notes
Due within one year:
Outstanding, Amount	$ 2,910,330	$ 2,822,454
Outstanding, Weighted - average rate	3.76%	4.02%
Average Outstanding, Amount	$ 2,832,154	$ 2,901,863
Average Outstanding, Weighted - average rate (as a percent)	3.75%	4.35%
Medium-term notes due in:
Two years	$ 6,176,103	$ 6,641,397
Three years	4,170,515	3,740,471
Four years	3,643,833	2,836,656
Five years	5,998,251	3,889,804
Thereafter	$ 1,871,732	2,435,870
Total due after one year		$ 19,544,198
Total weighted - average rate	3.63%	3.58%
Medium-term notes | Two years
Medium-term notes due in:
Weighted average rate	3.74%	3.65%
Medium-term notes | Three years
Medium-term notes due in:
Weighted average rate	3.98%	3.97%
Medium-term notes | Four years
Medium-term notes due in:
Weighted average rate	4.02%	4.24%
Medium-term notes | Five years
Medium-term notes due in:
Weighted average rate	3.67%	3.71%
Medium-term notes | Thereafter
Medium-term notes due in:
Weighted average rate	3.07%	2.88%
Medium-term notes | Total due after one year
Medium-term notes due in:
Weighted average rate	3.75%	3.71%
Current portion of medium-term notes
Due within one year:
Outstanding, Amount	$ 7,887,370	$ 5,834,657
Outstanding, Weighted - average rate	3.19%	2.77%