Guarantees and Commitments - Credit Quality Indicators (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Total
Total	$ 8,817,783		$ 8,817,783		$ 8,314,096
Current period, net charge offs	0		(84)
Agricultural Finance
Year One
Total	1,152,189		1,152,189		2,224,509
Current period charge-offs	0	$ 0	0	$ 0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Two
Total	2,122,700		2,122,700		1,596,563
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Three
Total	1,480,495		1,480,495		617,576
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Four
Total	540,959		540,959		400,104
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Five
Total	343,932		343,932		351,687
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Prior
Total	1,114,263		1,114,263		1,095,135
Current period charge-offs	0	0	(84)	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	(84)	0
Revolving Loans - Amortized Cost Basis
Total	620,620		620,620		561,419
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Total
Total	7,375,158		7,375,158		6,846,993
Current period charge-offs	0	0	(84)	0
Current period recoveries	0	0	0	0
Current period, net charge offs		0		0
Rural Infrastructure Finance
Year One
Total	584,273		584,273		242,570
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Two
Total	230,232		230,232		635,166
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Three
Total	634,474		634,474		774,941
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Four
Total	748,381		748,381		8,100
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Five
Total	7,932		7,932		86,878
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Prior
Total	653,100		653,100		628,903
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Revolving Loans - Amortized Cost Basis
Total	27,301		27,301		12,578
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Total
Total	2,885,693		2,885,693		2,389,136
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Acceptable | Agricultural Finance
Year One
Total	1,086,064		1,086,064		2,138,060
Year Two
Total	2,023,008		2,023,008		1,541,509
Year Three
Total	1,424,641		1,424,641		540,139
Year Four
Total	484,523		484,523		324,917
Year Five
Total	290,051		290,051		303,852
Prior
Total	1,009,207		1,009,207		1,004,709
Revolving Loans - Amortized Cost Basis
Total	593,106		593,106		545,370
Total
Total	6,910,600		6,910,600		6,398,556
Acceptable | Rural Infrastructure Finance
Year One
Total	584,273		584,273		242,570
Year Two
Total	230,232		230,232		612,366
Year Three
Total	634,474		634,474		774,941
Year Four
Total	748,381		748,381		8,100
Year Five
Total	7,932		7,932		86,878
Prior
Total	653,100		653,100		628,903
Revolving Loans - Amortized Cost Basis
Total	27,301		27,301		12,578
Total
Total	2,885,693		2,885,693		2,366,336
Special mention | Agricultural Finance
Year One
Total	64,238		64,238		84,795
Year Two
Total	89,605		89,605		50,057
Year Three
Total	33,431		33,431		51,200
Year Four
Total	32,408		32,408		48,078
Year Five
Total	35,735		35,735		9,132
Prior
Total	26,774		26,774		14,646
Revolving Loans - Amortized Cost Basis
Total	7,630		7,630		4,771
Total
Total	289,821		289,821		262,679
Special mention | Rural Infrastructure Finance
Year One
Total	0		0		0
Year Two
Total	0		0		0
Year Three
Total	0		0		0
Year Four
Total	0		0		0
Year Five
Total	0		0		0
Prior
Total	0		0		0
Revolving Loans - Amortized Cost Basis
Total	0		0		0
Total
Total	0		0		0
Substandard | Agricultural Finance
Year One
Total	1,887		1,887		1,654
Year Two
Total	10,087		10,087		4,997
Year Three
Total	22,423		22,423		26,237
Year Four
Total	24,028		24,028		27,109
Year Five
Total	18,146		18,146		38,703
Prior
Total	78,282		78,282		75,780
Revolving Loans - Amortized Cost Basis
Total	19,884		19,884		11,278
Total
Total	174,737		174,737		185,758
Substandard | Rural Infrastructure Finance
Year One
Total	0		0		0
Year Two
Total	0		0		22,800
Year Three
Total	0		0		0
Year Four
Total	0		0		0
Year Five
Total	0		0		0
Prior
Total	0		0		0
Revolving Loans - Amortized Cost Basis
Total	0		0		0
Total
Total	0		0		22,800
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance
Year One
Total	162,839		162,839		376,027
Current period charge-offs	0		0	0
Current period recoveries	0		0	0
Current period, net charge offs	0		0	0
Year Two
Total	491,124		491,124		544,098
Current period charge-offs	0		0	0
Current period recoveries	0		0	0
Current period, net charge offs	0		0	0
Year Three
Total	530,607		530,607		245,089
Current period charge-offs	0		0	0
Current period recoveries	0		0	0
Current period, net charge offs	0		0	0
Year Four
Total	247,696		247,696		200,298
Current period charge-offs	0		0	0
Current period recoveries	0		0	0
Current period, net charge offs	0		0	0
Year Five
Total	204,571		204,571		251,812
Current period charge-offs	0		0	0
Current period recoveries	0		0	0
Current period, net charge offs	0		0	0
Prior
Total	1,216,243		1,216,243		1,089,305
Current period charge-offs	0		0	0
Current period recoveries	0		0	0
Current period, net charge offs	0		0	0
Revolving Loans - Amortized Cost Basis
Total	280,312		280,312		258,127
Current period charge-offs	0		0	0
Current period recoveries	0		0	0
Current period, net charge offs	0		0	0
Total
Total	3,133,392		3,133,392		2,964,756
Current period charge-offs	0		0	0
Current period recoveries	0		0	0
Current period, net charge offs	0		0	0
LTSPCs and Farmer Mac Guaranteed Securities | Acceptable | Agricultural Finance
Year One
Total	162,839		162,839		376,027
Year Two
Total	489,795		489,795		537,521
Year Three
Total	529,605		529,605		244,365
Year Four
Total	247,696		247,696		188,452
Year Five
Total	199,766		199,766		235,865
Prior
Total	1,148,637		1,148,637		1,013,937
Revolving Loans - Amortized Cost Basis
Total	267,764		267,764		252,039
Total
Total	3,046,102		3,046,102		2,848,206
LTSPCs and Farmer Mac Guaranteed Securities | Special mention | Agricultural Finance
Year One
Total	0		0		0
Year Two
Total	1,329		1,329		5,270
Year Three
Total	826		826		0
Year Four
Total	0		0		6,808
Year Five
Total	1,209		1,209		3,154
Prior
Total	42,659		42,659		38,042
Revolving Loans - Amortized Cost Basis
Total	9,128		9,128		2,354
Total
Total	55,151		55,151		55,628
LTSPCs and Farmer Mac Guaranteed Securities | Substandard | Agricultural Finance
Year One
Total	0		0		0
Year Two
Total	0		0		1,307
Year Three
Total	176		176		724
Year Four
Total	0		0		5,038
Year Five
Total	3,596		3,596		12,793
Prior
Total	24,947		24,947		37,326
Revolving Loans - Amortized Cost Basis
Total	3,420		3,420		3,734
Total
Total	32,139		32,139		60,922
LTSPCs | Rural Infrastructure Finance
Year One
Total	0		0		0
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Two
Total	0		0		0
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Three
Total	0		0		0
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Four
Total	0		0		0
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Year Five
Total	0		0		0
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Prior
Total	482,427		482,427		499,594
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Revolving Loans - Amortized Cost Basis
Total	58,801		58,801		57,243
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	0	0	0
Total
Total	541,228		541,228		556,837
Current period charge-offs	0	0	0	0
Current period recoveries	0	0	0	0
Current period, net charge offs	0	$ 0	0	$ 0
LTSPCs | Acceptable | Rural Infrastructure Finance
Year One
Total	0		0		0
Year Two
Total	0		0		0
Year Three
Total	0		0		0
Year Four
Total	0		0		0
Year Five
Total	0		0		0
Prior
Total	482,427		482,427		499,594
Revolving Loans - Amortized Cost Basis
Total	58,801		58,801		57,243
Total
Total	541,228		541,228		556,837
LTSPCs | Special mention | Rural Infrastructure Finance
Year One
Total	0		0		0
Year Two
Total	0		0		0
Year Three
Total	0		0		0
Year Four
Total	0		0		0
Year Five
Total	0		0		0
Prior
Total	0		0		0
Revolving Loans - Amortized Cost Basis
Total	0		0		0
Total
Total	0		0		0
LTSPCs | Substandard | Rural Infrastructure Finance
Year One
Total	0		0		0
Year Two
Total	0		0		0
Year Three
Total	0		0		0
Year Four
Total	0		0		0
Year Five
Total	0		0		0
Prior
Total	0		0		0
Revolving Loans - Amortized Cost Basis
Total	0		0		0
Total
Total	$ 0		$ 0		$ 0