Note 4 - Fair Value Measurement - Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Jun. 30, 2016
US Treasury Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	$ 48,486	$ 48,774
US Treasury Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
US Treasury Securities [Member] | Fair Value, Measurements, Recurring [Member]
Securities available-for-sale	48,486	48,774
Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	13,348	13,385
Corporate Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Securities available-for-sale	13,348	13,385
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	30,403	32,223
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Measurements, Recurring [Member]
Securities available-for-sale	30,403	32,223
Mutual Fund Investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	1,455	1,462
Mutual Fund Investments [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Mutual Fund Investments [Member] | Fair Value, Measurements, Recurring [Member]
Securities available-for-sale	1,455	1,462
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	49,941	50,236
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	43,751	45,608
Fair Value, Measurements, Recurring [Member]
Securities available-for-sale	93,692	95,844
Securities available-for-sale	$ 93,692	$ 95,844