Guarantees and Commitments - Credit Quality Indicators (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Total
Total	$ 8,915,656		$ 9,008,979
Agricultural Finance
Total
Current period charge-offs	0	$ (84)
Rural Infrastructure Finance
Year One
Total	247,553		741,021
Current period charge-offs	0	0
Year Two
Total	727,714		220,420
Current period charge-offs	0	0
Year Three
Total	177,165		629,223
Current period charge-offs	0	0
Year Four
Total	619,983		739,270
Current period charge-offs	0	0
Year Five
Total	730,252		7,932
Current period charge-offs	0	0
Prior
Total	635,181		649,830
Current period charge-offs	0	0
Revolving Loans - Amortized Cost Basis
Total	40,256		33,570
Current period charge-offs	0	0
Total
Total	3,178,104		3,021,266
Current period charge-offs	0	0
Acceptable | Rural Infrastructure Finance
Year One
Total	247,553		741,021
Year Two
Total	727,714		220,420
Year Three
Total	177,165		629,223
Year Four
Total	619,983		739,270
Year Five
Total	730,252		7,932
Prior
Total	635,181		649,830
Revolving Loans - Amortized Cost Basis
Total	40,256		33,570
Total
Total	3,178,104		3,021,266
Special mention | Rural Infrastructure Finance
Year One
Total	0		0
Year Two
Total	0		0
Year Three
Total	0		0
Year Four
Total	0		0
Year Five
Total	0		0
Prior
Total	0		0
Revolving Loans - Amortized Cost Basis
Total	0		0
Total
Total	0		0
Substandard | Rural Infrastructure Finance
Year One
Total	0		0
Year Two
Total	0		0
Year Three
Total	0		0
Year Four
Total	0		0
Year Five
Total	0		0
Prior
Total	0		0
Revolving Loans - Amortized Cost Basis
Total	0		0
Total
Total	0		0
Long-Term Standby Purchase Commitments and Guaranteed Securities
Total
Total	3,705,064		3,714,184
Long-Term Standby Purchase Commitments and Guaranteed Securities | Agricultural Finance
Year One
Total	36,192		202,998
Current period charge-offs	0	0
Year Two
Total	232,884		497,588
Current period charge-offs	0	0
Year Three
Total	493,125		537,752
Current period charge-offs	0	0
Year Four
Total	531,462		254,293
Current period charge-offs	0	0
Year Five
Total	255,456		212,165
Current period charge-offs	0	0
Prior
Total	1,343,393		1,183,111
Current period charge-offs	0	0
Revolving Loans - Amortized Cost Basis
Total	308,964		303,085
Current period charge-offs	0	0
Total
Total	3,201,476		3,190,992
Current period charge-offs	0	0
Long-Term Standby Purchase Commitments and Guaranteed Securities | Acceptable | Agricultural Finance
Year One
Total	36,192		202,998
Year Two
Total	232,811		496,269
Year Three
Total	491,815		535,798
Year Four
Total	529,545		254,293
Year Five
Total	255,049		207,379
Prior
Total	1,273,859		1,107,834
Revolving Loans - Amortized Cost Basis
Total	302,452		296,508
Total
Total	3,121,723		3,101,079
Long-Term Standby Purchase Commitments and Guaranteed Securities | Special mention | Agricultural Finance
Year One
Total	0		0
Year Two
Total	73		1,319
Year Three
Total	1,310		1,778
Year Four
Total	1,763		0
Year Five
Total	0		1,198
Prior
Total	41,605		42,680
Revolving Loans - Amortized Cost Basis
Total	3,186		3,205
Total
Total	47,937		50,180
Long-Term Standby Purchase Commitments and Guaranteed Securities | Substandard | Agricultural Finance
Year One
Total	0		0
Year Two
Total	0		0
Year Three
Total	0		176
Year Four
Total	154		0
Year Five
Total	407		3,588
Prior
Total	27,929		32,597
Revolving Loans - Amortized Cost Basis
Total	3,326		3,372
Total
Total	31,816		39,733
Long-Term Standby Purchase Commitments | Rural Infrastructure Finance
Year One
Total	0		0
Current period charge-offs	0	0
Year Two
Total	0		0
Current period charge-offs	0	0
Year Three
Total	0		0
Current period charge-offs	0	0
Year Four
Total	0		0
Current period charge-offs	0	0
Year Five
Total	0		0
Current period charge-offs	0	0
Prior
Total	441,459		470,659
Current period charge-offs	0	0
Revolving Loans - Amortized Cost Basis
Total	62,129		52,533
Current period charge-offs	0	0
Total
Total	503,588		523,192
Current period charge-offs	0	$ 0
Long-Term Standby Purchase Commitments | Acceptable | Rural Infrastructure Finance
Year One
Total	0		0
Year Two
Total	0		0
Year Three
Total	0		0
Year Four
Total	0		0
Year Five
Total	0		0
Prior
Total	441,459		470,659
Revolving Loans - Amortized Cost Basis
Total	62,129		52,533
Total
Total	503,588		523,192
Long-Term Standby Purchase Commitments | Special mention | Rural Infrastructure Finance
Year One
Total	0		0
Year Two
Total	0		0
Year Three
Total	0		0
Year Four
Total	0		0
Year Five
Total	0		0
Prior
Total	0		0
Revolving Loans - Amortized Cost Basis
Total	0		0
Total
Total	0		0
Long-Term Standby Purchase Commitments | Substandard | Rural Infrastructure Finance
Year One
Total	0		0
Year Two
Total	0		0
Year Three
Total	0		0
Year Four
Total	0		0
Year Five
Total	0		0
Prior
Total	0		0
Revolving Loans - Amortized Cost Basis
Total	0		0
Total
Total	$ 0		$ 0