Fair Value of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2018

Fair Value Disclosures [Abstract]

Schedule of Fair Value Measurement

The following tables represent the financial instruments measured at fair value on a recurring basis on the financial statements of the Company and the valuation approach applied to each class of financial instruments at September 30, 2018 and December 31, 2017 (in thousands):

	September 30, 2018
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Cash and cash equivalents:
Money market funds	$	27,160	$	—	$	—	$	27,160
Commercial paper	—		2,644		—		2,644
Asset-backed securities	—		3,001		—		3,001
Total cash and cash equivalents	$	27,160	$	5,645	$	—	$	32,805
Investments:
Certificates of deposit	—		12,481		—		12,481
U.S. Treasury securities	34,268		—		—		34,268
U.S. Agency securities	—		7,951		—		7,951
Commercial paper	—		18,456		—		18,456
Asset-backed securities	—		11,967		—		11,967
Corporate notes and bonds	—		33,859		—		33,859
Total investments	34,268		84,714		—		118,982
Total assets measured at fair value	$	61,428	$	90,359	$	—	$	151,787

	December 31, 2017
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Cash and cash equivalents:
Money market funds	$	7,832	$	—	$	—	$	7,832
Investments:
Certificates of deposit	—		13,441		—		13,441
U.S. Treasury securities	14,716		—		—		14,716
U.S. Agency securities	—		8,459		—		8,459
Commercial paper	—		9,171		—		9,171
Asset-backed securities	—		3,025		—		3,025
Corporate notes and bonds	—		31,836		—		31,836
Total investments	14,716		65,932		—		80,648
Total assets measured at fair value	$	22,548	$	65,932	$	—	$	88,480