Marketable Securities - Fair Value, Amortized Cost and Unrealized Holding Gains (Losses) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Jun. 30, 2015
Short-term marketable securities
Marketable Securities
Fair Value	$ 9,025	$ 59,197
Cost	9,026	59,223
Unrealized Gains	1	8
Unrealized Losses	(2)	(34)
Long-term marketable securities
Marketable Securities
Fair Value		3,047
Cost		3,055
Unrealized Gains		0
Unrealized Losses		(8)
U.S. corporate bonds | Short-term marketable securities
Marketable Securities
Fair Value	9,025	59,197
Cost	9,026	59,223
Unrealized Gains	1	8
Unrealized Losses	$ (2)	(34)
U.S. corporate bonds | Long-term marketable securities
Marketable Securities
Fair Value		3,047
Cost		3,055
Unrealized Gains		0
Unrealized Losses		$ (8)