Guarantees and Commitments - Credit Quality Indicators (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Total
Total	$ 8,911,475		$ 8,911,475		$ 8,314,096
Current period, net charge offs	0		(84)
Agricultural Finance
Year One
Total	824,430		824,430		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	2,180,452		2,180,452		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	1,512,669		1,512,669		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	553,062		553,062		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	355,192		355,192		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	1,206,459		1,206,459		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	566,598		566,598		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	7,198,862		7,198,862		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	415,701		415,701		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	206,967		206,967		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	638,579		638,579		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	757,248		757,248		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	3,792		3,792		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	693,200		693,200		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	42,506		42,506		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	2,757,993		2,757,993		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	806,441		806,441		2,138,060
Year Two
Total	2,069,734		2,069,734		1,541,509
Year Three
Total	1,452,337		1,452,337		540,139
Year Four
Total	477,525		477,525		324,917
Year Five
Total	300,187		300,187		303,852
Prior
Total	1,100,135		1,100,135		1,004,709
Revolving Loans - Amortized Cost Basis
Total	537,395		537,395		545,370
Total
Total	6,743,754		6,743,754		6,398,556
Acceptable | Rural Infrastructure Finance
Year One
Total	415,701		415,701		242,570
Year Two
Total	206,967		206,967		612,366
Year Three
Total	638,579		638,579		774,941
Year Four
Total	757,248		757,248		8,100
Year Five
Total	3,792		3,792		86,878
Prior
Total	693,200		693,200		628,903
Revolving Loans - Amortized Cost Basis
Total	42,506		42,506		12,578
Total
Total	2,757,993		2,757,993		2,366,336
Special mention | Agricultural Finance
Year One
Total	17,989		17,989		84,795
Year Two
Total	104,734		104,734		50,057
Year Three
Total	40,616		40,616		51,200
Year Four
Total	50,915		50,915		48,078
Year Five
Total	34,897		34,897		9,132
Prior
Total	25,188		25,188		14,646
Revolving Loans - Amortized Cost Basis
Total	11,459		11,459		4,771
Total
Total	285,798		285,798		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	0		0		1,654
Year Two
Total	5,984		5,984		4,997
Year Three
Total	19,716		19,716		26,237
Year Four
Total	24,622		24,622		27,109
Year Five
Total	20,108		20,108		38,703
Prior
Total	81,136		81,136		75,780
Revolving Loans - Amortized Cost Basis
Total	17,744		17,744		11,278
Total
Total	169,310		169,310		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	77,240		77,240		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	448,463		448,463		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	508,637		508,637		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	237,501		237,501		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	190,161		190,161		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	1,202,651		1,202,651		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	264,567		264,567		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	2,929,220		2,929,220		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	77,240		77,240		376,027
Year Two
Total	442,971		442,971		537,521
Year Three
Total	504,112		504,112		244,365
Year Four
Total	236,781		236,781		188,452
Year Five
Total	183,049		183,049		235,865
Prior
Total	1,134,264		1,134,264		1,013,937
Revolving Loans - Amortized Cost Basis
Total	256,933		256,933		252,039
Total
Total	2,835,350		2,835,350		2,848,206
LTSPCs and Farmer Mac Guaranteed Securities | Special mention | Agricultural Finance
Year One
Total	0		0		0
Year Two
Total	0		0		5,270
Year Three
Total	1,882		1,882		0
Year Four
Total	0		0		6,808
Year Five
Total	1,219		1,219		3,154
Prior
Total	44,111		44,111		38,042
Revolving Loans - Amortized Cost Basis
Total	2,296		2,296		2,354
Total
Total	49,508		49,508		55,628
LTSPCs and Farmer Mac Guaranteed Securities | Substandard | Agricultural Finance
Year One
Total	0		0		0
Year Two
Total	5,492		5,492		1,307
Year Three
Total	2,643		2,643		724
Year Four
Total	720		720		5,038
Year Five
Total	5,893		5,893		12,793
Prior
Total	24,276		24,276		37,326
Revolving Loans - Amortized Cost Basis
Total	5,338		5,338		3,734
Total
Total	44,362		44,362		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	490,615		490,615		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	82,314		82,314		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	572,929		572,929		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	490,615		490,615		499,594
Revolving Loans - Amortized Cost Basis
Total	82,314		82,314		57,243
Total
Total	572,929		572,929		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