Loans - Schedule of Financing Receivables Credit Quality Indicators (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Total
Total	$ 8,314,096	$ 7,261,933
Current period charge-offs		5,800
Agricultural Finance
Year One
Total	2,224,509	2,021,189
Current period charge-offs	0	0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Year Two
Total	1,596,563	859,880
Current period charge-offs	0	0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Year Three
Total	617,576	524,541
Current period charge-offs	0	0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Year Four
Total	400,104	562,007
Current period charge-offs	0	5,365
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	5,365
Year Five
Total	351,687	515,561
Current period charge-offs	0	0
Current period recoveries	(1,054)	0
Current period Agricultural Finance recoveries	(1,054)	0
Prior
Total	1,095,135	1,140,603
Current period charge-offs	0	394
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	394
Revolving Loans - Amortized Cost Basis
Total	561,419	552,657
Current period charge-offs	0	0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Total
Total	6,846,993	6,176,438
Current period charge-offs	0	5,759	$ 67
Current period recoveries	(1,054)	0
Current period Agricultural Finance recoveries	(1,054)	5,759
Rural Infrastructure Finance
Year One
Total	242,570	667,489
Current period charge-offs	0	0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Year Two
Total	635,166	809,921
Current period charge-offs	0	0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Year Three
Total	774,941	8,260
Current period charge-offs	0	0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Year Four
Total	8,100	89,842
Current period charge-offs	0	0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Year Five
Total	86,878	31,275
Current period charge-offs	0	0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Prior
Total	628,903	641,145
Current period charge-offs	0	0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Revolving Loans - Amortized Cost Basis
Total	12,578	12,480
Current period charge-offs	0	0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Total
Total	2,389,136	2,260,412
Current period charge-offs	0	0	$ 0
Current period recoveries	0	0
Current period Agricultural Finance recoveries	0	0
Acceptable | Agricultural Finance
Year One
Total	2,138,060	1,947,618
Year Two
Total	1,541,509	774,315
Year Three
Total	540,139	484,345
Year Four
Total	324,917	500,768
Year Five
Total	303,852	465,277
Prior
Total	1,004,709	1,068,693
Revolving Loans - Amortized Cost Basis
Total	545,370	535,742
Total
Total	6,398,556	5,776,758
Acceptable | Rural Infrastructure Finance
Year One
Total	242,570	667,489
Year Two
Total	612,366	809,921
Year Three
Total	774,941	8,260
Year Four
Total	8,100	89,842
Year Five
Total	86,878	31,275
Prior
Total	628,903	641,145
Revolving Loans - Amortized Cost Basis
Total	12,578	12,480
Total
Total	2,366,336	2,260,412
Special mention | Agricultural Finance
Year One
Total	84,795	70,171
Year Two
Total	50,057	79,744
Year Three
Total	51,200	18,317
Year Four
Total	48,078	8,530
Year Five
Total	9,132	13,111
Prior
Total	14,646	21,328
Revolving Loans - Amortized Cost Basis
Total	4,771	7,656
Total
Total	262,679	218,857
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 | Agricultural Finance
Year One
Total	1,654	3,400
Year Two
Total	4,997	5,821
Year Three
Total	26,237	21,879
Year Four
Total	27,109	52,709
Year Five
Total	38,703	37,173
Prior
Total	75,780	50,582
Revolving Loans - Amortized Cost Basis
Total	11,278	9,259
Total
Total	185,758	180,823
Substandard | Rural Infrastructure Finance
Year One
Total	0	0
Year Two
Total	22,800	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	$ 22,800	$ 0