Loans - Troubled Debt Restructured Loans (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Nov. 30, 2021 USD ($) borrower	May 31, 2021 USD ($) borrower
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of total loans outstanding	100.00%	100.00%
Total TDR loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Borrowers | borrower	2	2
Outstanding amount | $	$ 9,434	$ 9,971
% of total loans outstanding	0.03%	0.04%
Performing TDR loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Borrowers | borrower	2	2
Outstanding amount | $	$ 9,434	$ 9,971
% of total loans outstanding	0.03%	0.04%
Parent Company
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of total loans outstanding	96.00%	96.00%
Parent Company | Distribution
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of total loans outstanding	78.00%	78.00%
Parent Company | Total TDR loans | Distribution
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Borrowers | borrower	1	1
Outstanding amount | $	$ 5,092	$ 5,379
% of total loans outstanding	0.02%	0.02%
RTFC
Financing Receivable, Troubled Debt Restructuring [Line Items]
% of total loans outstanding	1.00%	1.00%
RTFC | Total TDR loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Borrowers | borrower	1	1
Outstanding amount | $	$ 4,342	$ 4,592
% of total loans outstanding	0.01%	0.02%