Fair Value Measurements - Assets Carried at Fair Value Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Jun. 30, 2017
Assets:
Cash equivalents	$ 10,572	$ 13,521
Total cash equivalents	10,572	13,521
Quoted Prices in Active Markets (Level 1) [Member]
Assets:
Cash equivalents	10,572	13,521
Total cash equivalents	10,572	13,521
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Cash equivalents	0	0
Total cash equivalents	0	0
Significant Unobservable Inputs (Level 3) [Member]
Assets:
Cash equivalents	0	0
Total cash equivalents	$ 0	$ 0