Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Summary of Assets and Liabilities Carried at Fair Value

A summary of the assets and liabilities carried at fair value in accordance with the hierarchy defined above is as follows (in thousands):

	Fair Value Measurements Using
	Total Carrying Value		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
March 31, 2018 (unaudited)
Assets:
Money market funds	$	64,769	$	64,769	$	—	$	—
Corporate notes	103,580		—		103,580		—
Government notes	7,919		7,919		—		—
Total assets	$	176,268	$	72,688	$	103,580	$	—

	Fair Value Measurements Using
	Total Carrying Value		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
December 31, 2017:
Assets:
Money market funds	$	8,685	$	8,685	$	—	$	—
Corporate notes	46,098		5,103		40,995		—
Government notes	6,175		6,175		—		—
Total assets	$	60,958	$	19,963	$	40,995	$	—