Guarantees and Commitments - Credit Quality Indicators (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Total
Total	$ 9,129,176		$ 9,129,176		$ 9,008,979
Agricultural Finance
Total
Current period charge-offs	0	$ 0	0	$ 84
Rural Infrastructure Finance
Year One
Total	383,710		383,710		741,021
Current period charge-offs	0	0	0	0
Year Two
Total	732,146		732,146		220,420
Current period charge-offs	0	0	0	0
Year Three
Total	183,029		183,029		629,223
Current period charge-offs	0	0	0	0
Year Four
Total	610,440		610,440		739,270
Current period charge-offs	0	0	0	0
Year Five
Total	720,113		720,113		7,932
Current period charge-offs	0	0	0	0
Prior
Total	632,462		632,462		649,830
Current period charge-offs	0	0	0	0
Revolving Loans - Amortized Cost Basis
Total	44,867		44,867		33,570
Current period charge-offs	0	0	0	0
Total
Total	3,306,767		3,306,767		3,021,266
Current period charge-offs	0	0	0	0
Acceptable | Rural Infrastructure Finance
Year One
Total	383,710		383,710		741,021
Year Two
Total	732,146		732,146		220,420
Year Three
Total	183,029		183,029		629,223
Year Four
Total	610,440		610,440		739,270
Year Five
Total	720,113		720,113		7,932
Prior
Total	632,462		632,462		649,830
Revolving Loans - Amortized Cost Basis
Total	44,867		44,867		33,570
Total
Total	3,306,767		3,306,767		3,021,266
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 | 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
Rural Infrastructure Finance:
Total
Total	3,728,259		3,728,259		3,714,184
Rural Infrastructure Finance: | Agricultural Finance
Year One
Total	88,205		88,205		202,998
Current period charge-offs	0		0	0
Year Two
Total	225,185		225,185		497,588
Current period charge-offs	0		0	0
Year Three
Total	490,132		490,132		537,752
Current period charge-offs	0		0	0
Year Four
Total	532,981		532,981		254,293
Current period charge-offs	0		0	0
Year Five
Total	251,647		251,647		212,165
Current period charge-offs	0		0	0
Prior
Total	1,310,220		1,310,220		1,183,111
Current period charge-offs	0		0	0
Revolving Loans - Amortized Cost Basis
Total	339,475		339,475		303,085
Current period charge-offs	0		0	0
Total
Total	3,237,845		3,237,845		3,190,992
Current period charge-offs	0		0	0
Rural Infrastructure Finance: | Acceptable | Agricultural Finance
Year One
Total	80,415		80,415		202,998
Year Two
Total	225,112		225,112		496,269
Year Three
Total	488,832		488,832		535,798
Year Four
Total	531,946		531,946		254,293
Year Five
Total	250,650		250,650		207,379
Prior
Total	1,238,946		1,238,946		1,107,834
Revolving Loans - Amortized Cost Basis
Total	333,072		333,072		296,508
Total
Total	3,148,973		3,148,973		3,101,079
Rural Infrastructure Finance: | Special mention | Agricultural Finance
Year One
Total	7,790		7,790		0
Year Two
Total	73		73		1,319
Year Three
Total	1,300		1,300		1,778
Year Four
Total	881		881		0
Year Five
Total	0		0		1,198
Prior
Total	38,400		38,400		42,680
Revolving Loans - Amortized Cost Basis
Total	2,200		2,200		3,205
Total
Total	50,644		50,644		50,180
Rural Infrastructure Finance: | Substandard | Agricultural Finance
Year One
Total	0		0		0
Year Two
Total	0		0		0
Year Three
Total	0		0		176
Year Four
Total	154		154		0
Year Five
Total	997		997		3,588
Prior
Total	32,874		32,874		32,597
Revolving Loans - Amortized Cost Basis
Total	4,203		4,203		3,372
Total
Total	38,228		38,228		39,733
Long-Term Standby Purchase Commitments | Rural Infrastructure Finance
Year One
Total	0		0		0
Current period charge-offs	0	0	0	0
Year Two
Total	0		0		0
Current period charge-offs	0	0	0	0
Year Three
Total	0		0		0
Current period charge-offs	0	0	0	0
Year Four
Total	0		0		0
Current period charge-offs	0	0	0	0
Year Five
Total	0		0		0
Current period charge-offs	0	0	0	0
Prior
Total	433,896		433,896		470,659
Current period charge-offs	0	0	0	0
Revolving Loans - Amortized Cost Basis
Total	56,518		56,518		52,533
Current period charge-offs	0	0	0	0
Total
Total	490,414		490,414		523,192
Current period charge-offs	0	$ 0	0	$ 0
Long-Term Standby Purchase Commitments | 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	433,896		433,896		470,659
Revolving Loans - Amortized Cost Basis
Total	56,518		56,518		52,533
Total
Total	490,414		490,414		523,192
Long-Term Standby Purchase Commitments | 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
Long-Term Standby Purchase Commitments | 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