Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2016

Fair Value Disclosures [Abstract]

Financial Instruments Measured at Fair Value on Recurring Basis by Level within Fair Value Hierarchy

The following tables present our financial instruments that were measured at fair value on a recurring basis as of December 31, 2016 and 2015 by level within the fair value hierarchy (in thousands):

	December 31, 2016
	Level 1		Level 2		Level 3		Total
Financial Assets
Cash equivalents	$	21,834	$	—	$	—	$	21,834
Marketable securities:
Corporate bonds	—		522		—		522
	—		522		—		522
Total	$	21,834	$	522	$	—	$	22,356

	December 31, 2015
	Level 1		Level 2		Level 3		Total
Financial Assets
Cash equivalents	$	3	$	18,900	$	—	$	18,903
Marketable securities:
Corporate bonds	—		25,657		—		25,657
Asset-backed securities	—		12,393		—		12,393
Mortgage-backed securities	—		4,779		—		4,779
Government and agency securities	3,722		1,990		—		5,712
Municipal bonds	—		2,468		—		2,468
	3,722		47,287		—		51,009
Total	$	3,725	$	66,187	$	—	$	69,912
Financial Liabilities
Fair value of early conversion feature of convertible debt	$	—	$	—	$	82	$	82