Fair Value Disclosures - Fair Value Measurements, Recurring and Nonrecurring (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets:
Financial derivatives	$ 26,329	$ 19,139
Loans held for sale, at lower of cost or fair value	9,000	0
Investment securities:
Assets:
Fair Value	4,195,314	$ 3,836,391
Farmer Mac Guaranteed Securities
Assets:
Fair Value	$ 6,600,246
Level 3
Liabilities:
Percent of level three fair value assets and liabilities	26.00%	25.00%
Financial instruments level three percent	61.00%	62.00%
Recurring
Assets:
Financial derivatives	$ 26,329	$ 19,139
Total Assets at fair value	10,831,413	10,194,727
Liabilities:
Financial derivatives	105,574	34,248
Total Liabilities at fair value	105,574	34,248
Recurring \| USDA Securities:
Assets:
Trading	3,386	4,401
Recurring \| Investment securities:
Assets:
Fair Value	4,195,314	3,836,391
Recurring \| Farmer Mac Guaranteed Securities
Assets:
Fair Value	6,600,246	6,328,559
Recurring \| Level 1
Assets:
Financial derivatives	1,039	73
Guarantee Asset	0	0
Total Assets at fair value	1,391,615	1,179,542
Liabilities:
Financial derivatives	128	0
Total Liabilities at fair value	128	0
Recurring \| Level 1 \| USDA Securities:
Assets:
Trading	0	0
Recurring \| Level 1 \| Investment securities:
Assets:
Fair Value	1,390,576	1,179,469
Recurring \| Level 1 \| Farmer Mac Guaranteed Securities
Assets:
Fair Value	0	0
Recurring \| Level 2
Assets:
Financial derivatives	25,290	19,066
Guarantee Asset	0	0
Total Assets at fair value	2,811,067	2,656,734
Liabilities:
Financial derivatives	105,446	34,248
Total Liabilities at fair value	105,446	34,248
Recurring \| Level 2 \| USDA Securities:
Assets:
Trading	0	0
Recurring \| Level 2 \| Investment securities:
Assets:
Fair Value	2,785,777	2,637,668
Recurring \| Level 2 \| Farmer Mac Guaranteed Securities
Assets:
Fair Value	0	0
Recurring \| Level 3
Assets:
Financial derivatives	0	0
Guarantee Asset	6,138	6,237
Total Assets at fair value	6,628,731	6,358,451
Liabilities:
Financial derivatives	0	0
Total Liabilities at fair value	0	0
Recurring \| Level 3 \| USDA Securities:
Assets:
Trading	3,386	4,401
Recurring \| Level 3 \| Investment securities:
Assets:
Fair Value	18,961	19,254
Recurring \| Level 3 \| Farmer Mac Guaranteed Securities
Assets:
Fair Value	6,600,246	6,328,559
Fair Value, Nonrecurring
Assets:
Mortgage Servicing Rights		2,681
Loans held for sale, at lower of cost or fair value	9,300
Total Assets at fair value	9,300	2,681
Fair Value, Nonrecurring \| Level 1
Assets:
Mortgage Servicing Rights		0
Loans held for sale, at lower of cost or fair value	0
Total Assets at fair value	0	0
Fair Value, Nonrecurring \| Level 2
Assets:
Mortgage Servicing Rights		0
Loans held for sale, at lower of cost or fair value	0
Total Assets at fair value	0	0
Fair Value, Nonrecurring \| Level 3
Assets:
Mortgage Servicing Rights		2,681
Loans held for sale, at lower of cost or fair value	9,300
Total Assets at fair value	9,300	2,681
AgVantage Securities \| Recurring \| Farmer Mac Guaranteed Securities
Assets:
Fair Value	6,589,224	6,316,145
AgVantage Securities \| Recurring \| Level 1 \| Farmer Mac Guaranteed Securities
Assets:
Fair Value	0	0
AgVantage Securities \| Recurring \| Level 2 \| Farmer Mac Guaranteed Securities
Assets:
Fair Value	0	0
AgVantage Securities \| Recurring \| Level 3 \| Farmer Mac Guaranteed Securities
Assets:
Fair Value	6,589,224	6,316,145
Farmer Mac Guaranteed USDA Securities \| Recurring \| Level 1 \| Farmer Mac Guaranteed Securities
Assets:
Fair Value	0	0
Farmer Mac Guaranteed USDA Securities \| Recurring \| Level 2 \| Farmer Mac Guaranteed Securities
Assets:
Fair Value	0	0
Farmer Mac Guaranteed USDA Securities \| Recurring \| Level 3 \| Farmer Mac Guaranteed Securities
Assets:
Fair Value	11,022	12,414
USDA Securities \| Recurring \| USDA Securities:
Assets:
Trading	3,386	4,401
USDA Securities \| Recurring \| Level 1 \| USDA Securities:
Assets:
Trading	0	0
USDA Securities \| Recurring \| Level 2 \| USDA Securities:
Assets:
Trading	0	0
USDA Securities \| Recurring \| Level 3 \| USDA Securities:
Assets:
Trading	3,386	4,401
Floating Interest Rate \| Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Fair Value	18,961	19,254
Floating Interest Rate \| Guaranteed mortgage-backed securities
Assets:
Fair Value	2,265,157	2,178,831
Floating Interest Rate \| Recurring \| Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Fair Value	18,961	19,254
Floating Interest Rate \| Recurring \| Guaranteed mortgage-backed securities
Assets:
Fair Value	2,265,157	2,178,831
Floating Interest Rate \| Recurring \| Level 1 \| Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Fair Value	0	0
Floating Interest Rate \| Recurring \| Level 1 \| Guaranteed mortgage-backed securities
Assets:
Fair Value	0	0
Floating Interest Rate \| Recurring \| Level 2 \| Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Fair Value	0	0
Floating Interest Rate \| Recurring \| Level 2 \| Guaranteed mortgage-backed securities
Assets:
Fair Value	2,265,157	2,178,831
Floating Interest Rate \| Recurring \| Level 3 \| Floating rate auction-rate certificates backed by Government guaranteed student loans
Assets:
Fair Value	18,961	19,254
Floating Interest Rate \| Recurring \| Level 3 \| Guaranteed mortgage-backed securities
Assets:
Fair Value	0	0
Fixed Interest Rate \| Guaranteed mortgage-backed securities
Assets:
Fair Value	520,620	458,837
Fixed Interest Rate \| Fixed rate U.S. Treasuries
Assets:
Fair Value	1,390,576	1,179,469
Fixed Interest Rate \| Recurring \| Guaranteed mortgage-backed securities
Assets:
Fair Value	520,620	458,837
Fixed Interest Rate \| Recurring \| Fixed rate U.S. Treasuries
Assets:
Fair Value	1,390,576	1,179,469
Fixed Interest Rate \| Recurring \| Level 1 \| Guaranteed mortgage-backed securities
Assets:
Fair Value	0	0
Fixed Interest Rate \| Recurring \| Level 1 \| Fixed rate U.S. Treasuries
Assets:
Fair Value	1,390,576	1,179,469
Fixed Interest Rate \| Recurring \| Level 2 \| Guaranteed mortgage-backed securities
Assets:
Fair Value	520,620	458,837
Fixed Interest Rate \| Recurring \| Level 2 \| Fixed rate U.S. Treasuries
Assets:
Fair Value	0	0
Fixed Interest Rate \| Recurring \| Level 3 \| Guaranteed mortgage-backed securities
Assets:
Fair Value	0	0
Fixed Interest Rate \| Recurring \| Level 3 \| Fixed rate U.S. Treasuries
Assets:
Fair Value	$ 0	$ 0

Fair Value, Assets and Liabilities Fair Value as Percent of Total Assets

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Fair Value, Assets and Liabilities, Fair Value as Percent of Total Financial Instruments Measured at Fair Value

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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