BUSINESS SEGMENT REPORTING - Schedule of Segment Reporting Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Interest income	$ 1,603,516	$ 1,392,288	$ 716,848
Interest expense	(1,249,649)	(1,064,741)	(445,908)
Less: reconciling adjustments	(14,303)	(567)	(15,411)
Net effective spread	339,564	326,980	255,529
Guarantee and commitment fees	20,321	18,928	18,144
Other income/(expense)	2,188	3,019	1,681
(Provision for)/release of losses	(11,490)	(1,136)	(806)
Operating expenses	(59,404)	(52,417)	(44,606)
Income tax (expense)/benefit	(61,148)	(62,029)	(48,288)
Segment core earnings	230,031	233,345	181,654
Reconciliation to net income:
Net effects of derivatives and trading securities	13,141	1,954	33,715
Unallocated (expenses)/income	(46,217)	(44,227)	(37,978)
Income tax effect related to reconciling items	10,238	8,931	753
Net income	207,193	200,003	178,144
Total on- and off-balance sheet segment assets at principal balance	29,523,030	28,471,024	25,922,082
Off-balance sheet assets under management	(4,981,285)	(4,710,199)	(3,945,557)
Unallocated assets	6,782,997	5,763,557	5,356,585
Total Assets	31,324,742	29,524,382	27,333,110
Operating Segments | Farm & Ranch
Segment Reporting Information [Line Items]
Interest income	615,016	559,730	421,139
Interest expense	(475,248)	(422,651)	(287,921)
Net effective spread	135,310	132,900	129,057
Guarantee and commitment fees	17,695	17,415	16,718
Other income/(expense)	3,167	2,952	1,420
(Provision for)/release of losses	(1,147)	(507)	(1,216)
Operating expenses	(24,741)	(23,306)	(23,332)
Income tax (expense)/benefit	(27,360)	(27,183)	(25,756)
Segment core earnings	102,924	102,271	96,891
Reconciliation to net income:
Total on- and off-balance sheet segment assets at principal balance	18,606,968	18,808,801	17,728,792
Operating Segments | Corporate AgFinance
Segment Reporting Information [Line Items]
Interest income	100,820	92,335	55,311
Interest expense	(70,695)	(61,111)	(26,102)
Net effective spread	30,125	31,224	29,209
Guarantee and commitment fees	571	283	139
Other income/(expense)	(2,055)	35	261
(Provision for)/release of losses	(6,850)	(207)	(2,136)
Operating expenses	(7,905)	(5,540)	(5,629)
Income tax (expense)/benefit	(2,916)	(5,418)	(4,587)
Segment core earnings	10,970	20,377	17,257
Reconciliation to net income:
Total on- and off-balance sheet segment assets at principal balance	1,887,705	1,693,979	1,603,507
Operating Segments | Power & Utilities
Segment Reporting Information [Line Items]
Interest income	260,636	232,106	152,990
Interest expense	(240,600)	(215,763)	(141,176)
Net effective spread	19,987	16,175	11,711
Guarantee and commitment fees	966	1,090	1,187
Other income/(expense)	0	0	0
(Provision for)/release of losses	274	4,117	3,726
Operating expenses	(4,281)	(3,553)	(3,198)
Income tax (expense)/benefit	(3,559)	(3,746)	(2,819)
Segment core earnings	13,387	14,083	10,607
Reconciliation to net income:
Total on- and off-balance sheet segment assets at principal balance	6,809,366	6,979,570	6,042,996
Operating Segments | Broadband Infrastructure
Segment Reporting Information [Line Items]
Interest income	38,225	30,299	8,832
Interest expense	(27,282)	(21,455)	(4,471)
Net effective spread	10,943	8,844	4,361
Guarantee and commitment fees	464	43	51
Other income/(expense)	0	0	0
(Provision for)/release of losses	1,469	(4,324)	(705)
Operating expenses	(3,666)	(2,415)	(2,009)
Income tax (expense)/benefit	(1,934)	(453)	(357)
Segment core earnings	7,276	1,695	1,341
Reconciliation to net income:
Total on- and off-balance sheet segment assets at principal balance	802,466	501,153	316,617
Operating Segments | Renewable Energy
Segment Reporting Information [Line Items]
Interest income	54,188	18,923	5,811
Interest expense	(40,471)	(14,275)	(3,328)
Net effective spread	13,717	4,648	2,483
Guarantee and commitment fees	625	97	49
Other income/(expense)	0	0	0
(Provision for)/release of losses	(5,236)	(219)	(494)
Operating expenses	(4,848)	(3,382)	(1,690)
Income tax (expense)/benefit	(894)	(238)	(73)
Segment core earnings	3,364	906	275
Reconciliation to net income:
Total on- and off-balance sheet segment assets at principal balance	1,416,525	487,521	230,170
Operating Segments | Funding
Segment Reporting Information [Line Items]
Interest income	224,390	200,264	(8,334)
Interest expense	(89,698)	(71,849)	104,947
Net effective spread	124,896	132,009	85,466
Guarantee and commitment fees	0	0	0
Other income/(expense)	0	3	0
(Provision for)/release of losses	0	0	0
Operating expenses	(10,855)	(11,037)	(6,798)
Income tax (expense)/benefit	(23,949)	(25,405)	(16,521)
Segment core earnings	90,092	95,570	62,147
Reconciliation to net income:
Total on- and off-balance sheet segment assets at principal balance	0	0	0
Operating Segments | Investments
Segment Reporting Information [Line Items]
Interest income	310,241	258,631	81,099
Interest expense	(305,655)	(257,637)	(87,857)
Net effective spread	4,586	1,180	(6,758)
Guarantee and commitment fees	0	0	0
Other income/(expense)	1,076	29	0
(Provision for)/release of losses	0	4	19
Operating expenses	(3,108)	(3,184)	(1,950)
Income tax (expense)/benefit	(536)	414	1,825
Segment core earnings	2,018	(1,557)	(6,864)
Reconciliation to net income:
Total on- and off-balance sheet segment assets at principal balance	0	0	0
Reconciling Adjustments | Farm & Ranch
Segment Reporting Information [Line Items]
Less: reconciling adjustments	(4,458)	(4,179)	(4,161)
Reconciling Adjustments | Corporate AgFinance
Segment Reporting Information [Line Items]
Less: reconciling adjustments	0	0	0
Reconciling Adjustments | Power & Utilities
Segment Reporting Information [Line Items]
Less: reconciling adjustments	(49)	(168)	(103)
Reconciling Adjustments | Broadband Infrastructure
Segment Reporting Information [Line Items]
Less: reconciling adjustments	0	0	0
Reconciling Adjustments | Renewable Energy
Segment Reporting Information [Line Items]
Less: reconciling adjustments	0	0	0
Reconciling Adjustments | Funding
Segment Reporting Information [Line Items]
Less: reconciling adjustments	(9,796)	3,594	(11,147)
Reconciling Adjustments | Investments
Segment Reporting Information [Line Items]
Less: reconciling adjustments	$ 0	$ 186	$ 0