Guarantees and Commitments - Unpaid Principal Balances by Delinquency Status (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Guarantor Obligations [Line Items]
Total	$ 9,130,933	$ 9,008,979
Agricultural Finance
Guarantor Obligations [Line Items]
Total	3,867,746	3,714,184
Current
Guarantor Obligations [Line Items]
Total	10,885,584	10,459,282
Current | Agricultural Finance
Guarantor Obligations [Line Items]
Total	3,856,137	3,698,131
Total Past Due
Guarantor Obligations [Line Items]
Total	27,712	11,598
Total Past Due | Agricultural Finance
Guarantor Obligations [Line Items]
Total	11,609	16,053
30-59 Days
Guarantor Obligations [Line Items]
Total	15,652	10,066
30-59 Days | Agricultural Finance
Guarantor Obligations [Line Items]
Total	5,196	11,614
60-89 Days
Guarantor Obligations [Line Items]
Total	5,321	392
60-89 Days | Agricultural Finance
Guarantor Obligations [Line Items]
Total	3,573	622
90 Days and Greater
Guarantor Obligations [Line Items]
Total	6,739	1,140
90 Days and Greater | Agricultural Finance
Guarantor Obligations [Line Items]
Total	2,840	3,817
Agricultural Finance | Agricultural Finance
Guarantor Obligations [Line Items]
Total	3,380,229	3,190,992
Agricultural Finance | Current
Guarantor Obligations [Line Items]
Total	7,542,871	7,438,016
Agricultural Finance | Current | Agricultural Finance
Guarantor Obligations [Line Items]
Total	3,368,620	3,174,939
Agricultural Finance | Total Past Due
Guarantor Obligations [Line Items]
Total	27,712	11,598
Agricultural Finance | Total Past Due | Agricultural Finance
Guarantor Obligations [Line Items]
Total	11,609	16,053
Agricultural Finance | 30-59 Days
Guarantor Obligations [Line Items]
Total	15,652	10,066
Agricultural Finance | 30-59 Days | Agricultural Finance
Guarantor Obligations [Line Items]
Total	5,196	11,614
Agricultural Finance | 60-89 Days
Guarantor Obligations [Line Items]
Total	5,321	392
Agricultural Finance | 60-89 Days | Agricultural Finance
Guarantor Obligations [Line Items]
Total	3,573	622
Agricultural Finance | 90 Days and Greater
Guarantor Obligations [Line Items]
Total	6,739	1,140
Agricultural Finance | 90 Days and Greater | Agricultural Finance
Guarantor Obligations [Line Items]
Total	2,840	3,817
Rural Infrastructure Finance
Guarantor Obligations [Line Items]
Total	3,342,713	3,021,266
Rural Infrastructure Finance | Rural Infrastructure Finance
Guarantor Obligations [Line Items]
Total	487,517	523,192
Rural Infrastructure Finance | Current
Guarantor Obligations [Line Items]
Total	3,342,713	3,021,266
Rural Infrastructure Finance | Current | Rural Infrastructure Finance
Guarantor Obligations [Line Items]
Total	487,517	523,192
Rural Infrastructure Finance | Total Past Due
Guarantor Obligations [Line Items]
Total	0	0
Rural Infrastructure Finance | Total Past Due | Rural Infrastructure Finance
Guarantor Obligations [Line Items]
Total	0	0
Rural Infrastructure Finance | 30-59 Days
Guarantor Obligations [Line Items]
Total	0	0
Rural Infrastructure Finance | 30-59 Days | Rural Infrastructure Finance
Guarantor Obligations [Line Items]
Total	0	0
Rural Infrastructure Finance | 60-89 Days
Guarantor Obligations [Line Items]
Total	0	0
Rural Infrastructure Finance | 60-89 Days | Rural Infrastructure Finance
Guarantor Obligations [Line Items]
Total	0	0
Rural Infrastructure Finance | 90 Days and Greater
Guarantor Obligations [Line Items]
Total	0	0
Rural Infrastructure Finance | 90 Days and Greater | Rural Infrastructure Finance
Guarantor Obligations [Line Items]
Total	$ 0	$ 0