Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2017

Fair Value Measurement

Schedule of the financial instruments measured at fair value and classified by level according to the fair value measurement hierarchy

(in thousands)	Level 1		Level 2		Level 3		Total
December 31, 2017
Assets:
Short-term investments:
Available-for-sale securities	$	—	$	50	$	—	$	50
Term deposits		60		—		—		60
Total Assets	$	60	$	50	$	—	$	110

(in thousands)	Level 1		Level 2		Level 3		Total
December 31, 2016
Assets:
Short-term investments:
Available-for-sale securities	$	15,017	$	36,059	$	—	$	51,076
Term deposits		30		—		—		30
Total Assets	$	15,047	$	36,059	$	—	$	51,106