Fair Value of Financial Instruments

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value of Financial Instruments

2. Fair Value of Financial Instruments

The estimated fair values of the Company’s financial instruments, which include cash equivalents, accounts receivable, accounts payable and other accrued liabilities approximate their carrying values due to the short-term nature of these instruments. The Company records marketable securities at amortized cost, which approximates fair value.

The Company’s fair value hierarchy for its cash equivalents and marketable securities as of March 31, 2018 and December 31, 2017, respectively, was as follows:

March 31, 2018	Level 1		Level 2		Level 3		Total
Money market securities	$	1,082	$	—	$	—	$	1,082
Commercial paper		—		50,997		—		50,997
Federal agency notes		—		5,006		—		5,006
Corporate notes		—		3,744		—		3,744
U.S. treasuries		—		2,000		—		2,000
Total	$	1,082	$	61,747	$	—	$	62,829

December 31, 2017	Level 1		Level 2		Level 3		Total
Money market securities	$	2,197	$	—	$	—	$	2,197
Commercial paper		—		49,834		—		49,834
Federal agency notes		—		10,715		—		10,715
U.S. treasuries		—		1,996		—		1,996
Corporate notes		—		1,934		—		1,934
Total	$	2,197	$	64,479	$	—	$	66,676

The fair value maturities of the Company’s cash equivalents and marketable securities as of March 31, 2018 are as follows:

	Maturities by Period
	Total		Lessthan 1 year		1-5 years		5 - 10 years		More than 10 years
Cash equivalents and marketable securities	$	62,829	$	62,829	$	—	$	—	$	—

The Company considers all highly liquid marketable securities with original maturities of 90 days or less at the date of acquisition to be cash equivalents. Cash equivalents include money market funds and commercial paper totaling $47,610 and $39,761 at March 31, 2018 and December 31, 2017, respectively. Cash equivalents are carried at cost or amortized cost, which approximates fair value.