Loans - Schedules of Concentration of Risk (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Feb. 28, 2023 USD ($) borrower	May 31, 2022 USD ($) borrower	Feb. 28, 2022 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of borrowers | borrower	880	883
Loans to members	$ 32,381,829	$ 30,063,386	$ 29,520,381
Power supply
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of borrowers | borrower	51	49
Loans covered under Farmer Mac standby purchase commitment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to members	$ 443,000	$ 493,000
TEXAS | Accounts receivable | Geographic concentration risk
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of borrowers | borrower	69	68
Loans to members	$ 5,480,527	$ 5,110,349
Concentration risk, percentage	17.00%	17.00%
TEXAS | Accounts receivable | Geographic concentration risk | Loans covered under Farmer Mac standby purchase commitment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to members	$ 157,098	$ 163,369
Concentration risk, percentage	1.00%	1.00%
TEXAS | Accounts receivable | Geographic concentration risk | Loans not covered under Farmer Mac standby purchase commitment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to members	$ 5,323,429	$ 4,946,980
Concentration risk, percentage	16.00%	16.00%
Parent Company | TEXAS | Accounts receivable | Geographic concentration risk
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of borrowers | borrower	66	66
Loans to members	$ 5,451,814	$ 5,104,118
Concentration risk, percentage	17.00%	17.00%
Parent Company | TEXAS | Accounts receivable | Geographic concentration risk | Distribution
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of borrowers | borrower	57	57
Loans to members	$ 4,284,930	$ 3,984,887
Concentration risk, percentage	13.00%	13.00%
Parent Company | TEXAS | Accounts receivable | Geographic concentration risk | Power supply
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of borrowers | borrower	8	8
Loans to members	$ 1,128,456	$ 1,089,896
Concentration risk, percentage	4.00%	4.00%
Parent Company | TEXAS | Accounts receivable | Geographic concentration risk | Statewide and associate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of borrowers | borrower	1	1
Loans to members	$ 38,428	$ 29,335
Concentration risk, percentage	0.00%	0.00%
NCSC | TEXAS | Accounts receivable | Geographic concentration risk
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of borrowers | borrower	1	1
Loans to members	$ 16,400	$ 378
Concentration risk, percentage	0.00%	0.00%
RTFC | TEXAS | Accounts receivable | Geographic concentration risk
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of borrowers | borrower	2	1
Loans to members	$ 12,313	$ 5,853
Concentration risk, percentage	0.00%	0.00%