Marketable Securities - Components of Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Jun. 30, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 62,396	$ 86,154
Gross Unrealized Gain	12	50
Gross Unrealized (Loss)	(80)	(38)
Fair Value	62,328	86,166
Certificates of Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	8,000	6,000
Gross Unrealized Gain		4
Gross Unrealized (Loss)	(3)
Fair Value	7,997	6,004
U.S. Treasury Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	9,751	13,375
Gross Unrealized Gain		14
Gross Unrealized (Loss)	(12)
Fair Value	9,739	13,389
U.S. Government Sponsored Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	25,868	40,694
Gross Unrealized Gain	12	30
Gross Unrealized (Loss)	(24)	(9)
Fair Value	25,856	40,715
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	18,777	26,085
Gross Unrealized Gain		2
Gross Unrealized (Loss)	(41)	(29)
Fair Value	$ 18,736	$ 26,058