Fair value disclosures (Tables)

6 Months Ended

Jun. 30, 2019

Fair Value Disclosures [Abstract]

Fair Value of Financial Assets

The following table presents the Company's assets and liabilities that are measured at fair value on a recurring basis (in thousands):

	As of June 30, 2019								As of December 31, 2018
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Short-term investments:
Money market funds	$	7,567	$	—	$	—	$	7,567	$	7,481	$	—	$	—	$	7,481
Other long-term assets:
Mutual funds held in Rabbi Trust	$	560	$	—	$	—	$	560	$	465	$	—	$	—	$	465
Liabilities
Accrued and other current liabilities:
Rusnano payment derivative	$	—	$	—	$	—	$	—	$	—	$	—	$	2,000	$	2,000

Fair Value of Financial Liabilities

The following table presents the Company's assets and liabilities that are measured at fair value on a recurring basis (in thousands):

	As of June 30, 2019								As of December 31, 2018
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Short-term investments:
Money market funds	$	7,567	$	—	$	—	$	7,567	$	7,481	$	—	$	—	$	7,481
Other long-term assets:
Mutual funds held in Rabbi Trust	$	560	$	—	$	—	$	560	$	465	$	—	$	—	$	465
Liabilities
Accrued and other current liabilities:
Rusnano payment derivative	$	—	$	—	$	—	$	—	$	—	$	—	$	2,000	$	2,000