Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2017

Fair Value Measurements [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, 2017						Fair Value at December 31, 2016
	Level 1		Level 2		Level 3		Level 1		Level 2		Level 3
Assets
Money market funds(1)	$	51,816	$	—	$	—	$	95,896	$	—	$	—
Government-backed securities		—		19,000		—		—		19,000		—
Asset-backed securities(2)		—		48,573		—		—		23,632		—
Corporate debt securities(3)		—		76,249		—		—		79,470		—
Total assets	$	51,816	$	143,822	$	—	$	95,896	$	122,102	$	—
Liabilities
Convertible notes payable	$	—	$	148,671	$	—	$	—	$	141,989	$	—

(1) Classified as cash and cash equivalents as of March 31, 2017 and December 31, 2016, respectively (see Note 3).

(2) Includes $3,500 classified as cash and cash equivalents as of March 31, 2017 (see Note 3).

(3) Includes $5,991 and $11,976 classified as cash and cash equivalents as of March 31, 2017 and December 31, 2016, respectively (see Note 3).