Loans - Unpaid Principal Balances by Delinquency Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	$ 9,011,820	$ 8,314,096
Nonaccrual loans	78,965	126,807
Total loans	10,549,845	9,236,129
Nonaccrual loans with no associated allowance	22,000	31,000
Interest received on nonaccrual loans	5,600	5,000
Current period charge-offs			$ 5,800
Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	6,362,326	5,723,693
Nonaccrual loans	63,402	126,807
Total loans	6,362,326	5,723,693
Total	1,252,022	1,872,895
Total	1,781,621	1,355,852
Total	1,236,079	455,799
Total	395,895	307,840
Total	265,661	319,070
Total	1,032,986	1,047,783
Total	398,062	364,454
Current period charge-offs	(84)	0	5,759
Financing Receivable, Originated in Current Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated Two Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated Three Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated Four Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	(1,054)
Financing Receivable, Originated Five or More Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Revolving, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Current period recoveries	0	(1,054)
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	(84)	0
Current period charge-offs	0	0
Farm & Ranch | Acceptable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	5,986,083	5,342,239
Total	1,157,829	1,786,446
Total	1,704,547	1,300,798
Total	1,187,474	399,394
Total	360,704	277,061
Total	242,491	271,234
Total	947,535	957,357
Total	385,503	349,949
Farm & Ranch | Special mention
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	221,816	195,696
Total	91,099	84,795
Total	68,260	50,057
Total	25,629	30,168
Total	11,254	3,670
Total	5,325	9,133
Total	17,797	14,646
Total	2,452	3,227
Farm & Ranch | Substandard
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	154,427	185,758
Total	3,094	1,654
Total	8,814	4,997
Total	22,976	26,237
Total	23,937	27,109
Total	17,845	38,703
Total	67,654	75,780
Total	10,107	11,278
Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,166,253	1,123,300
Nonaccrual loans	15,563	0
Total loans	1,166,253	1,123,300
Total	145,263	351,614
Total	299,729	240,712
Total	226,158	161,773
Total	128,928	92,263
Total	76,454	32,618
Total	44,827	47,360
Total	244,894	196,960
Current period charge-offs	0	0	0
Financing Receivable, Originated in Current Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated Two Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated Three Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated Four Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Revolving, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Current period recoveries	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Corporate AgFinance | Acceptable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,128,170	1,056,317
Total	145,263	351,614
Total	299,729	240,712
Total	221,560	140,742
Total	108,230	47,856
Total	76,454	32,618
Total	44,827	47,360
Total	232,107	195,415
Corporate AgFinance | Special mention
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	22,843	66,983
Total	0	0
Total	0	0
Total	0	21,031
Total	20,698	44,407
Total	0	0
Total	0	0
Total	2,145	1,545
Corporate AgFinance | Substandard
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	15,240	0
Total	0	0
Total	0	0
Total	4,598	0
Total	0	0
Total	0	0
Total	0	0
Total	10,642	0
Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	78,965	126,807
Total loans	7,528,579	6,846,993
Current period charge-offs	(84)		5,759
Current period recoveries		(1,054)
Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	3,021,266	2,389,136
Nonaccrual loans	0	0
Total loans	3,021,266	2,389,136
Total	741,021	242,570
Total	220,420	635,166
Total	629,223	774,941
Total	739,270	8,100
Total	7,932	86,878
Total	649,830	628,903
Total	33,570	12,578
Current period charge-offs	0	0	$ 0
Financing Receivable, Originated in Current Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated in Fiscal Year before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated Two Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated Three Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated Four Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Originated Five or More Years before Latest Fiscal Year, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Financing Receivable, Revolving, Excluding Accrued Interest, Allowance for Credit Loss, Recovery	0	0
Current period recoveries	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Current period charge-offs	0	0
Rural Infrastructure Finance | Acceptable
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	3,021,266	2,366,336
Total	741,021	242,570
Total	220,420	612,366
Total	629,223	774,941
Total	739,270	8,100
Total	7,932	86,878
Total	649,830	628,903
Total	33,570	12,578
Rural Infrastructure Finance | Special mention
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	0
Total	0	0
Total	0	0
Total	0	0
Total	0	0
Total	0	0
Total	0	0
Total	0	0
Rural Infrastructure Finance | Substandard
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	22,800
Total	0	0
Total	0	22,800
Total	0	0
Total	0	0
Total	0	0
Total	0	0
Total	0	0
Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	10,459,282	9,104,206
Current | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	6,287,326	5,591,770
Current | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,150,690	1,123,300
Current | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	7,438,016	6,715,070
Current | Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	3,021,266	2,389,136
Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	11,598	5,116
Total Past Due | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	11,598	5,116
Total Past Due | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	0
Total Past Due | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	11,598	5,116
Total Past Due | Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	0
30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	10,066	4,548
30-59 Days | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	10,066	4,548
30-59 Days | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	0
30-59 Days | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	10,066	4,548
30-59 Days | Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	0
60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	392	568
60-89 Days | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	392	568
60-89 Days | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	0
60-89 Days | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	392	568
60-89 Days | Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	0
90 Days and Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,140	0
90 Days and Greater | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,140	0
90 Days and Greater | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	0	0
90 Days and Greater | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	1,140	0
90 Days and Greater | Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total	$ 0	$ 0