Fair Value Measurement (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Jun. 30, 2017
Available-for-Sale Securities
Mutual funds	$ 3,528	$ 9,043
Held-to-maturity securities, maturities less than 1 year	1,623	1,607
Held-to-maturity securities, remaining maturities from 1-3 years		1,441
Held-to-maturity securities, maturities from 91-360 days	496	250
Held-to-maturity securities, maturities over 360 days	50	549
Investments	5,697	12,890
Mutual funds, fair value	3,528	9,043
Held-to-maturity securities, maturities less than 1 year, fair value	1,623	1,607
Held-to-maturity securities, remaining maturities from 1-3 years, fair value		1,441
Held-to-maturity securities, maturities from 91-360 days, fair value	496	250
Held-to-maturity securities, maturities over 360 days, fair value	50	549
Investments, fair value	5,697	12,890
Level 1
Available-for-Sale Securities
Mutual funds, fair value	3,528	9,043
Held-to-maturity securities, maturities less than 1 year, fair value	0	0
Held-to-maturity securities, remaining maturities from 1-3 years, fair value		0
Held-to-maturity securities, maturities from 91-360 days, fair value	0	0
Held-to-maturity securities, maturities over 360 days, fair value	0	0
Investments, fair value	3,528	9,043
Level 2
Available-for-Sale Securities
Mutual funds, fair value	0	0
Held-to-maturity securities, maturities less than 1 year, fair value	1,623	1,607
Held-to-maturity securities, remaining maturities from 1-3 years, fair value		1,441
Held-to-maturity securities, maturities from 91-360 days, fair value	496	250
Held-to-maturity securities, maturities over 360 days, fair value	50	549
Investments, fair value	2,169	3,847
Level 3
Available-for-Sale Securities
Mutual funds, fair value	0	0
Held-to-maturity securities, maturities less than 1 year, fair value	0	0
Held-to-maturity securities, remaining maturities from 1-3 years, fair value		0
Held-to-maturity securities, maturities from 91-360 days, fair value	0	0
Held-to-maturity securities, maturities over 360 days, fair value	0	0
Investments, fair value	$ 0	$ 0