NOTES PAYABLE - Borrowings (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Due within one year:
Outstanding, Amount	$ 10,146,575	$ 10,437,623
Outstanding, Weighted - average rate	3.52%	3.77%
Medium-term notes due in:
Two years	$ 6,426,273
Three years	3,903,276
Four years	2,540,026
Five years	3,545,517
Thereafter	2,642,823
Total due after one year	19,057,915
Total principal net of discounts	29,204,490	$ 27,520,173
Hedging adjustments	(7,710)	(148,999)
Total	$ 29,196,780	27,371,174
Weighted - average rate	3.67%
Total weighted - average rate	3.61%
Two years
Medium-term notes due in:
Weighted - average rate	3.42%
Three years
Medium-term notes due in:
Weighted - average rate	3.91%
Four years
Medium-term notes due in:
Weighted - average rate	4.40%
Five years
Medium-term notes due in:
Weighted - average rate	3.97%
Thereafter
Medium-term notes due in:
Weighted - average rate	2.80%
Discount notes
Due within one year:
Outstanding, Amount	$ 1,697,407	$ 2,167,258
Outstanding, Weighted - average rate	4.02%	4.42%
Average Outstanding, Amount	$ 1,652,951	$ 1,928,884
Average Outstanding, Weighted - average rate (as a percent)	4.24%	5.11%
Medium-term notes
Due within one year:
Outstanding, Amount	$ 3,229,398	$ 2,343,264
Outstanding, Weighted - average rate	4.20%	4.64%
Average Outstanding, Amount	$ 3,312,239	$ 1,000,290
Average Outstanding, Weighted - average rate (as a percent)	4.30%	5.28%
Medium-term notes due in:
Two years		$ 4,844,538
Three years		3,822,999
Four years		2,732,980
Five years		2,491,831
Thereafter		3,190,202
Total due after one year		$ 17,082,550
Weighted - average rate		3.34%
Total weighted - average rate		3.51%
Medium-term notes | Two years
Medium-term notes due in:
Weighted - average rate		2.66%
Medium-term notes | Three years
Medium-term notes due in:
Weighted - average rate		3.53%
Medium-term notes | Four years
Medium-term notes due in:
Weighted - average rate		4.13%
Medium-term notes | Five years
Medium-term notes due in:
Weighted - average rate		4.41%
Medium-term notes | Thereafter
Medium-term notes due in:
Weighted - average rate		2.63%
Current portion of medium-term notes
Due within one year:
Outstanding, Amount	$ 5,219,770	$ 5,927,101
Outstanding, Weighted - average rate	2.94%	3.20%