Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2019

Fair Value Disclosures [Abstract]

Fair Value Hierarchy

The following table represents the Company’s fair value hierarchy for its financial assets and liabilities measured at fair value (in thousands):

	Fair Value at March 31, 2019						Fair Value at December 31, 2018
	Level 1		Level 2		Level 3		Level 1		Level 2		Level 3
Assets
Money market funds(1)	$	49,113	$	―	$	―	$	39,168	$	―	$	―
Asset-backed securities(2)		―		15,000		―		―		19,997		―
Corporate debt securities(3)		―		26,712		―		―		26,219		―
Total assets	$	49,113	$	41,712	$	―	$	39,168	$	46,216	$	―
Liabilities
Convertible notes payable	$	―	$	117,267	$	―	$	―	$	197,935	$	―

(1)	Classified as cash and cash equivalents as of March 31, 2019 and December 31, 2018, respectively, on the consolidated balance sheets.
(2)	Includes $15,000 classified as cash and cash equivalents as of both March 31, 2019 and December 31, 2018 on the consolidated balance sheets.
(3)	Includes $24,228 and $9,236 classified as cash and cash equivalents as of March 31, 2019 and December 31, 2018, respectively, on the consolidated balance sheet.