Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 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 June 30, 2018 and December 31, 2017 (in thousands):

	June 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	$	37,824	$	—	$	—	$	37,824
Commercial paper	—		5,982		—		5,982
Corporate notes and bonds	—		9,087		—		9,087
Total cash and cash equivalents	$	37,824	$	15,069	$	—	$	52,893
Investments:
Certificates of deposit	—		13,682		—		13,682
U.S. Treasury securities	31,744		—		—		31,744
U.S. Agency securities	—		6,944		—		6,944
Commercial paper	—		35,917		—		35,917
Asset-backed securities	—		8,993		—		8,993
Corporate notes and bonds	—		33,314		—		33,314
Total investments	31,744		98,850		—		130,594
Total assets measured at fair value	$	69,568	$	113,919	$	—	$	183,487

	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