Cash, Cash Equivalents, and Short-Term Investments - Summary of Cash, Cash Equivalents and Short-Term Investments (Detail) $ in Thousands	Mar. 31, 2017 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 8,344
Unrealized Gain	0
Unrealized (Loss)	0
Estimated Fair Value	8,344
Cash [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	654
Unrealized Gain	0
Unrealized (Loss)	0
Estimated Fair Value	654
Money Market Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,387
Unrealized Gain	0
Unrealized (Loss)	0
Estimated Fair Value	5,387
U.S. Government Treasury Bills [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	601
Unrealized Gain	0
Unrealized (Loss)	0
Estimated Fair Value	601
Corporate Bonds and Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,702
Unrealized Gain	0
Unrealized (Loss)	0
Estimated Fair Value	1,702
Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Gain	0
Unrealized (Loss)	0
Estimated Fair Value	6,041
Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized Gain	0
Unrealized (Loss)	0
Estimated Fair Value	$ 2,303