Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2018

Fair Value Measurements

Schedule of financial instruments measured at fair value by level within the fair value hierarchy

	Level 1		Level 2		Level 3
September 30, 2018
Assets:
Cash and cash equivalents	$	16,818	$	—	$	—
Total assets at fair value	$	16,818	$	—	$	—
Liabilities:
Common stock warrants	$	—	$	—	$	—
Total liabilities at fair value	$	—	$	—	$	—

	Level 1		Level 2		Level 3
December 31, 2017
Assets:
Cash and cash equivalents	$	35,870	$	—	$	—
Total assets at fair value	$	35,870	$	—	$	—
Liabilities:
Common stock warrants	$	—	$	—	$	29
Total liabilities at fair value	$	—	$	—	$	29

Schedule of rollforward of the fair value of Level 3 warrants

Beginning balance at December 31, 2015	$	406
Change in fair value		(234)
Ending balance at December 31, 2016		172
Change in fair value		(143)
Ending balance at December 31, 2017		29
Change in fair value		(29)
Ending balance at September 30, 2018	$	—