Employee Benefits - Narrative (Details) $ in Thousands	12 Months Ended
	May 31, 2023 USD ($) participant hour salary	May 31, 2022 USD ($) participant	May 31, 2021 USD ($)	Jan. 01, 2023	Jan. 01, 2022	Jan. 01, 2021
Defined benefit multiemployer master pension plan
Multiemployer plans requisite service period	1 year
Percentage of joint and surviving spouse annuity	50.00%
Annuity factor (as a percent)	1.70%
Number of highest base salaries | salary	5
Contributions made by CFC	$ 5,000	$ 5,000	$ 4,000
Liability, defined benefit pension plan	5,000	5,000
Contributions by employer	1,000	2,000	1,000
Payment for settlement	1,000	2,000	1,000
Accumulated other comprehensive income	8,343	2,258
Defined benefit plan, net periodic benefit cost (credit), gain (loss) due to settlement and curtailment (less than $1 million in fiscal year 2023 and 2022)	$ 1,000	1,000	1,000
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Settlement and Curtailment Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Noninterest Expense
Number of consecutive months considered for eligible period of service	12 months
Maximum matching contributions by CFC as a percentage of employee's salary	2.00%
Minimum employee contribution (as a percent)	2.00%
Contributions made by CFC	$ 1,000	$ 1,000	$ 1,000
Minimum
Defined benefit multiemployer master pension plan
Funded status, more than 80% (as a percent)				80.00%	80.00%	80.00%
Requisite service period | hour	1,000
Maximum
Defined benefit multiemployer master pension plan
Contributions made by CFC as a percentage of total contributions by all participating employers	5.00%	5.00%	5.00%
Executive benefit restoration plan
Defined benefit multiemployer master pension plan
Number of participants | participant	7	3
Pension expense	$ 1,000	$ 1,000	$ 2,000
Accumulated other comprehensive income expected to be reclassified into earnings over the next 12 months	1,000
Accumulated other comprehensive income	$ 3,000	$ 3,000