Loans - Schedule of Composition of Loan Balances (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	$ 9,236,129	$ 8,436,850
Total	8,314,096	7,261,933
Allowance for losses	(14,041)	(13,832)
Total loans, net of allowance	9,248,678	8,535,146
Real Estate Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	9,236,129	8,436,850
Unamortized premiums, discounts, fair value hedge basis adjustment, and other cost basis adjustments	26,590	112,128
Total	9,262,719	8,548,978
Allowance for losses	(14,041)	(13,832)
Total loans, net of allowance	9,248,678	8,535,146
Agricultural Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	6,846,993	6,176,438
Total	6,846,993	6,176,438
Allowance for losses	(3,442)	(3,745)
Agricultural Finance | Real Estate Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	6,846,993	6,176,438
Rural Infrastructure Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	2,389,136	2,260,412
Total	2,389,136	2,260,412
Allowance for losses	(10,599)	(10,087)
Rural Infrastructure Finance | Real Estate Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	2,389,136	2,260,412
Unsecuritized
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	8,287,506	7,149,805
Unamortized premiums, discounts, fair value hedge basis adjustment, and other cost basis adjustments	26,590	112,128
Total	8,314,096	7,261,933
Allowance for losses	(13,477)	(12,943)
Total loans, net of allowance	8,300,619	7,248,990
Unsecuritized | Agricultural Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	5,898,370	4,889,393
Unsecuritized | Rural Infrastructure Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	2,389,136	2,260,412
In Consolidated Trusts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	948,623	1,287,045
Unamortized premiums, discounts, fair value hedge basis adjustment, and other cost basis adjustments	0	0
Total	948,623	1,287,045
Allowance for losses	(564)	(889)
Total loans, net of allowance	948,059	1,286,156
In Consolidated Trusts | Agricultural Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	948,623	1,287,045
In Consolidated Trusts | Rural Infrastructure Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid principal balance	$ 0	$ 0