Fair Value Disclosures - Summary of Carrying Value and Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financial assets:
Financial derivatives	$ 26,329	$ 19,139
Guarantee and commitment fees receivable	45,021	45,538
Financial liabilities:
Guarantee and commitment obligation	43,285	43,926
Fair Value
Financial assets:
Cash and cash equivalents	890,046	908,785
Loans	9,429,186	9,814,642
Financial derivatives	26,329	19,139
Guarantee and commitment fees receivable	43,279	42,533
Financial liabilities:
Notes payable	22,596,306	22,716,791
Debt securities of consolidated trusts held by third parties	890,823	1,005,306
Financial derivatives	105,574	34,248
Guarantee and commitment obligation	41,542	40,920
Fair Value | Investment securities:
Financial assets:
Marketable securities	4,241,418	3,884,202
Fair Value | Farmer Mac Guaranteed Securities
Financial assets:
Marketable securities	8,476,067	8,360,293
Fair Value | USDA Securities:
Financial assets:
Marketable securities	2,395,117	2,536,473
Carrying Amount
Financial assets:
Cash and cash equivalents	890,046	908,785
Loans	9,364,940	9,248,678
Financial derivatives	26,329	19,139
Guarantee and commitment fees receivable	45,021	45,538
Financial liabilities:
Notes payable	23,039,967	22,716,156
Debt securities of consolidated trusts held by third parties	895,145	981,379
Financial derivatives	105,574	34,248
Guarantee and commitment obligation	43,285	43,926
Carrying Amount | Investment securities:
Financial assets:
Marketable securities	4,241,788	3,882,590
Carrying Amount | Farmer Mac Guaranteed Securities
Financial assets:
Marketable securities	8,506,464	8,361,798
Carrying Amount | USDA Securities:
Financial assets:
Marketable securities	$ 2,439,489	$ 2,440,732