Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2018

Financial Instruments Owned At Fair Value [Abstract]

Summary of Cash Equivalents and Short and Long-term Investments

Cash equivalents and short- and long-term investments consisted of the following (in thousands):

	December 31,
	2018						2017
	Amortized		Unrealized		Fair		Amortized		Unrealized			Fair
	Cost		Gains (Losses)		Value		Cost		Gains (Losses)			Value
Cash equivalents:
Money market funds	$	109,265	$	—	$	109,265	$	104,544	$	—		$	104,544
Certificate of deposit		7,000		—		7,000		7,814		—			7,814
Marketable securities:
Corporate bonds		15,194		40		15,234		17,758		(57	)		17,701
Commercial paper		9,889		76		9,965		7,456		20			7,476
U.S. treasury securities		12,300		38		12,338		12,381		26			12,407
	$	153,648	$	154	$	153,802	$	149,953	$	(11	)	$	149,942
Due within one year					$	153,802						$	144,736
Due within two years						—							5,206
Total					$	153,802						$	149,942

Summary of Financial Assets Measured at Fair Value on a Recurring Basis

The following table presents information about our financial assets that are measured at fair value on a recurring basis and indicates the fair value hierarchy of the valuation techniques utilized to determine such fair value (in thousands):

	Level 1		Level 2		Level 3		Total
Assets at December 31, 2018:
Cash equivalents:
Money market funds	$	109,265	$	—	$	—	$	109,265
Certificate of deposit		7,000		—		—		7,000
Marketable securities:
Corporate bonds		—		15,234		—		15,234
Commercial paper		—		9,965		—		9,965
U.S. treasury securities		—		12,338		—		12,338
	$	116,265	$	37,537	$	—	$	153,802

Liabilities at December 31, 2018:
Earn-out liability	$	—	$	—	$	1,368	$	1,368
	$	—	$	—	$	1,368	$	1,368

Assets at December 31, 2017:
Cash equivalents:
Money market funds	$	104,544	$	—	$	—	$	104,544
Certificate of deposit		7,814		—		—		7,814
Marketable securities:
Corporate bonds		—		17,701		—		17,701
Commercial paper		—		7,476		—		7,476
U.S. treasury securities		—		12,407		—		12,407
	$	112,358	$	37,584	$	—	$	149,942