Short-term Investments - Summary of Investments in a Continuous Loss Position (Details) $ in Thousands	Jun. 30, 2017 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair value	$ 42,540
Less Than 12 Months, Gross unrealized losses	(53)
12 Months or Greater, Fair value	0
12 Months or Greater, Gross unrealized losses	0
Total, Fair value	42,540
Total, Gross unrealized losses	(53)
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair value	31,061
Less Than 12 Months, Gross unrealized losses	(28)
12 Months or Greater, Fair value	0
12 Months or Greater, Gross unrealized losses	0
Total, Fair value	31,061
Total, Gross unrealized losses	(28)
U.S. government-related debt securities
Schedule of Available-for-sale Securities [Line Items]
Less Than 12 Months, Fair value	11,479
Less Than 12 Months, Gross unrealized losses	(25)
12 Months or Greater, Fair value	0
12 Months or Greater, Gross unrealized losses	0
Total, Fair value	11,479
Total, Gross unrealized losses	$ (25)