Guarantees and Commitments - Unpaid Principal Balances by Delinquency Status (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Guarantor Obligations [Line Items]
Total	$ 8,911,475	$ 8,314,096
Current
Guarantor Obligations [Line Items]
Total	9,834,986	9,104,206
Total Past Due
Guarantor Obligations [Line Items]
Total	13,291	5,116
30-59 Days
Guarantor Obligations [Line Items]
Total	9,546	4,548
60-89 Days
Guarantor Obligations [Line Items]
Total	265	568
90 Days and Greater
Guarantor Obligations [Line Items]
Total	3,480	0
Agricultural Finance
Guarantor Obligations [Line Items]
Total	7,198,862	6,846,993
Agricultural Finance | Current
Guarantor Obligations [Line Items]
Total	7,076,993	6,715,070
Agricultural Finance | Total Past Due
Guarantor Obligations [Line Items]
Total	13,291	5,116
Agricultural Finance | 30-59 Days
Guarantor Obligations [Line Items]
Total	9,546	4,548
Agricultural Finance | 60-89 Days
Guarantor Obligations [Line Items]
Total	265	568
Agricultural Finance | 90 Days and Greater
Guarantor Obligations [Line Items]
Total	3,480	0
Rural Infrastructure Finance
Guarantor Obligations [Line Items]
Total	2,757,993	2,389,136
Rural Infrastructure Finance | Current
Guarantor Obligations [Line Items]
Total	2,757,993	2,389,136
Rural Infrastructure Finance | Total Past Due
Guarantor Obligations [Line Items]
Total	0	0
Rural Infrastructure Finance | 30-59 Days
Guarantor Obligations [Line Items]
Total	0	0
Rural Infrastructure Finance | 60-89 Days
Guarantor Obligations [Line Items]
Total	0	0
Rural Infrastructure Finance | 90 Days and Greater
Guarantor Obligations [Line Items]
Total	0	0
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance
Guarantor Obligations [Line Items]
Total	2,929,220	2,964,756
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance | Current
Guarantor Obligations [Line Items]
Total	2,913,144	2,953,091
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance | Total Past Due
Guarantor Obligations [Line Items]
Total	16,076	11,665
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance | 30-59 Days
Guarantor Obligations [Line Items]
Total	14,009	8,068
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance | 60-89 Days
Guarantor Obligations [Line Items]
Total	194	0
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance | 90 Days and Greater
Guarantor Obligations [Line Items]
Total	1,873	3,597
LTSPCs | Rural Infrastructure Finance
Guarantor Obligations [Line Items]
Total	572,929	556,837
LTSPCs | Rural Infrastructure Finance | Current
Guarantor Obligations [Line Items]
Total	572,929	556,837
LTSPCs | Rural Infrastructure Finance | Total Past Due
Guarantor Obligations [Line Items]
Total	0	0
LTSPCs | Rural Infrastructure Finance | 30-59 Days
Guarantor Obligations [Line Items]
Total	0	0
LTSPCs | Rural Infrastructure Finance | 60-89 Days
Guarantor Obligations [Line Items]
Total	0	0
LTSPCs | Rural Infrastructure Finance | 90 Days and Greater
Guarantor Obligations [Line Items]
Total	$ 0	$ 0