Guarantees and Commitments - Unpaid Principal Balances by Delinquency Status (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Guarantor Obligations [Line Items]
Total	$ 8,817,783	$ 8,314,096
Current
Guarantor Obligations [Line Items]
Total	10,163,316	9,104,206
Total Past Due
Guarantor Obligations [Line Items]
Total	13,328	5,116
30-59 Days
Guarantor Obligations [Line Items]
Total	4,665	4,548
60-89 Days
Guarantor Obligations [Line Items]
Total	2,424	568
90 Days and Greater
Guarantor Obligations [Line Items]
Total	6,239	0
Agricultural Finance
Guarantor Obligations [Line Items]
Total	7,375,158	6,846,993
Agricultural Finance | Current
Guarantor Obligations [Line Items]
Total	7,277,623	6,715,070
Agricultural Finance | Total Past Due
Guarantor Obligations [Line Items]
Total	13,328	5,116
Agricultural Finance | 30-59 Days
Guarantor Obligations [Line Items]
Total	4,665	4,548
Agricultural Finance | 60-89 Days
Guarantor Obligations [Line Items]
Total	2,424	568
Agricultural Finance | 90 Days and Greater
Guarantor Obligations [Line Items]
Total	6,239	0
Rural Infrastructure Finance
Guarantor Obligations [Line Items]
Total	2,885,693	2,389,136
Rural Infrastructure Finance | Current
Guarantor Obligations [Line Items]
Total	2,885,693	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	3,133,392	2,964,756
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance | Current
Guarantor Obligations [Line Items]
Total	3,127,963	2,953,091
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance | Total Past Due
Guarantor Obligations [Line Items]
Total	5,429	11,665
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance | 30-59 Days
Guarantor Obligations [Line Items]
Total	2,586	8,068
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance | 60-89 Days
Guarantor Obligations [Line Items]
Total	626	0
LTSPCs and Farmer Mac Guaranteed Securities | Agricultural Finance | 90 Days and Greater
Guarantor Obligations [Line Items]
Total	2,217	3,597
LTSPCs | Rural Infrastructure Finance
Guarantor Obligations [Line Items]
Total	541,228	556,837
LTSPCs | Rural Infrastructure Finance | Current
Guarantor Obligations [Line Items]
Total	541,228	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