Fair Value Measurements and Fair Value of Financial Instruments, Fair Value, Assets and Liabilities Measured on Nonrecurring Basis (Details) - Nonrecurring [Member] $ in Thousands	6 Months Ended
	Dec. 31, 2017 USD ($) Approach	Jun. 30, 2017 USD ($)
Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Recorded investment	$ 2,377	$ 1,822
Related allowance	533	436
Fair value	$ 1,844	1,386
Impaired Loans [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of approaches used for appraisals | Approach	3
Foreclosed Real Estate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Recorded investment	$ 905	799
Related allowance	0	0
Fair value	905	799
Level 1 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	0	0
Level 1 [Member] | Foreclosed Real Estate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	0	0
Level 2 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	0	0
Level 2 [Member] | Foreclosed Real Estate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	0	0
Level 3 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	1,844	1,386
Level 3 [Member] | Foreclosed Real Estate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	$ 905	$ 799