Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2019

Fair Value Disclosures [Abstract]

Schedule of fair value of financial instruments

	December 31, 2019
	Level 1		Level 2		Level 3		Total
Financial Assets:
Money market funds	$	—	$	—	$	—	$	—
Corporate fixed income debt securities		—		—		—		—
Total	$	—	$	—	$	—	$	—
Financial Liabilities:
Common stock warrant liability (1)	$	—	$	—	$	—	$	—
Total	$	—	$	—	$	—	$	—

	December 31, 2018
	Level 1		Level 2		Level 3		Total
Financial Assets:
Money market funds	$	3	$	—	$	—	$	—
Corporate fixed income debt securities		—		—		—		—
Total	$	—	$	—	$	—	$	—
Financial Liabilities:
Common stock warrant liability (1)	$	—	$	—	$	—	$	—
Total	$	—	$	—	$	—	$	—

(1) The change in the fair value of the common stock warrant and convertible notes payable for the twelve months ended December 31, 2019 and 2018 was recorded as a decrease to other income (expense) and interest expense of $0 and $1, respectively, in the statements of operations and comprehensive loss.