Fair Value of Financial Instruments - Corporations assets measured at fair value at the dates indicated on a nonrecurring basis (Details) - Nonrecurring - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-performing loans	$ 6,616	$ 8,646
Mortgage servicing assets	132	208
Total assets	6,748	8,854
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-performing loans	0	0
Mortgage servicing assets	0	0
Total assets	0	0
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-performing loans	713	899
Mortgage servicing assets	0	0
Total assets	713	899
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-performing loans	5,903	7,747
Mortgage servicing assets	132	208
Total assets	$ 6,035	$ 7,955