NOTES PAYABLE - Borrowings (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Due within one year:
Outstanding, Amount	$ 8,870,013	$ 8,087,168
Outstanding, Weighted - average rate	3.63%	3.52%
Medium-term notes due in:
Two years	$ 4,972,023
Three years	4,064,733
Four years	2,568,251
Five years	2,941,652
Thereafter	3,398,246
Total due after one year	17,944,905
Total principal net of discounts	26,814,918	$ 26,586,959
Hedging adjustments	(305,907)	(250,417)
Total	$ 26,509,011	26,336,542
Weighted - average rate	3.21%
Total weighted - average rate	3.35%
Two years
Medium-term notes due in:
Weighted - average rate	2.95%
Three years
Medium-term notes due in:
Weighted - average rate	2.60%
Four years
Medium-term notes due in:
Weighted - average rate	3.84%
Five years
Medium-term notes due in:
Weighted - average rate	4.45%
Thereafter
Medium-term notes due in:
Weighted - average rate	2.76%
Discount notes
Due within one year:
Outstanding, Amount	$ 1,898,810	$ 1,734,387
Outstanding, Weighted - average rate	5.23%	5.32%
Average Outstanding, Amount	$ 1,662,014	$ 1,097,300
Average Outstanding, Weighted - average rate (as a percent)	5.25%	5.08%
Medium-term notes
Due within one year:
Outstanding, Amount	$ 366,953	$ 384,970
Outstanding, Weighted - average rate	5.28%	5.07%
Average Outstanding, Amount	$ 272,528	$ 1,731,308
Average Outstanding, Weighted - average rate (as a percent)	5.23%	4.09%
Medium-term notes due in:
Two years		$ 5,523,671
Three years		3,825,702
Four years		3,038,229
Five years		2,623,202
Thereafter		3,488,987
Total due after one year		$ 18,499,791
Weighted - average rate		3.16%
Total weighted - average rate		3.27%
Medium-term notes | Two years
Medium-term notes due in:
Weighted - average rate		3.27%
Medium-term notes | Three years
Medium-term notes due in:
Weighted - average rate		2.27%
Medium-term notes | Four years
Medium-term notes due in:
Weighted - average rate		3.44%
Medium-term notes | Five years
Medium-term notes due in:
Weighted - average rate		4.37%
Medium-term notes | Thereafter
Medium-term notes due in:
Weighted - average rate		2.80%
Current portion of medium-term notes
Due within one year:
Outstanding, Amount	$ 6,604,250	$ 5,967,811
Outstanding, Weighted - average rate	3.08%	2.90%