Fair Value Measurements - Summary of Financial Assets that were Accounted for at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Jun. 30, 2017
Financial assets
Amortized Cost	$ 70,925	$ 96,082
Gross Unrealized Gains	355
Gross Unrealized Losses		(89)
Cash and cash equivalents	70,392	72,084
Short-term investments	888	23,909
Cash
Financial assets
Amortized Cost	70,392	70,515
Cash and cash equivalents	70,392	70,515
Level 2 | Corporate securities
Financial assets
Amortized Cost	533
Gross Unrealized Gains	355
Short-term investments	$ 888
Level 2 | U.S. government agency securities
Financial assets
Amortized Cost		23,998
Gross Unrealized Losses		(89)
Short-term investments		23,909
Level 1 | Money market funds
Financial assets
Amortized Cost		1,569
Cash and cash equivalents		$ 1,569