Fair Value Disclosures - Summary of Carrying Value and Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Financial assets:
Financial derivatives	$ 49,968	$ 6,081
Guarantee and commitment fees receivable	46,347	45,538
Financial liabilities:
Financial derivatives	184,554	35,554
Guarantee and commitment obligation	45,726	43,926
Fair Value
Financial assets:
Cash and cash equivalents	868,234	908,785
Loans	8,965,973	9,814,642
Financial derivatives	49,968	6,081
Guarantee and commitment fees receivable	49,328	42,533
Financial liabilities:
Notes payable	22,578,047	22,716,791
Debt securities of consolidated trusts held by third parties	977,411	1,005,306
Financial derivatives	184,554	35,554
Guarantee and commitment obligation	48,705	40,920
Fair Value | Investment securities:
Financial assets:
Marketable securities	4,447,259	3,884,202
Fair Value | Farmer Mac Guaranteed Securities
Financial assets:
Marketable securities	8,239,615	8,360,293
Fair Value | USDA Securities:
Financial assets:
Marketable securities	2,032,548	2,536,473
Carrying Amount
Financial assets:
Cash and cash equivalents	868,234	908,785
Loans	9,925,184	9,248,678
Financial derivatives	49,968	6,081
Guarantee and commitment fees receivable	46,347	45,538
Financial liabilities:
Notes payable	23,500,657	22,713,771
Debt securities of consolidated trusts held by third parties	1,090,539	981,379
Financial derivatives	184,554	35,554
Guarantee and commitment obligation	45,726	43,926
Carrying Amount | Investment securities:
Financial assets:
Marketable securities	4,449,017	3,882,590
Carrying Amount | Farmer Mac Guaranteed Securities
Financial assets:
Marketable securities	8,302,041	8,361,798
Carrying Amount | USDA Securities:
Financial assets:
Marketable securities	$ 2,430,489	$ 2,440,732