Cash, Cash Equivalents, And Available-For-Sale Securities (Tables)

3 Months Ended

Mar. 31, 2019

CASH, CASH EQUIVALENTS, AND AVAILABLE-FOR-SALE SECURITIES

Schedule of fair value and amortized cost of cash, cash equivalents, and available-for-sale securities by major security type

	As of March 31, 2019
			Gross		Gross
	Amortized		Unrealized		Unrealized		Estimated
Cash and cash equivalents and available-for-sale securities	Cost		Gains		Losses		Fair Value
Cash and money market funds	$	23,021	$	—	$	—	$	23,021
U.S. Treasury securities		39,004		51		(59)		38,996
Corporate debt securities		42,649		77		(90)		42,636
Total		104,674		128		(149)		104,653
Less amounts classified as cash and cash equivalents		(23,021)		—		—		(23,021)
Total available-for-sale securities	$	81,653	$	128	$	(149)	$	81,632

	As of December 31, 2018
			Gross		Gross
	Amortized		Unrealized		Unrealized		Estimated
Cash and cash equivalents and available-for-sale securities	Cost		Gains		Losses		Fair Value
Cash and money market funds	$	30,411	$	—	$	—	$	30,411
U.S. Treasury securities		42,261		34		(111)		42,184
Corporate debt securities		38,848		9		(203)		38,654
Total		111,520		43		(314)		111,249
Less amounts classified as cash and cash equivalents		(30,411)		—		—		(30,411)
Total available-for-sale securities	$	81,109	$	43	$	(314)	$	80,838

Schedule of Fair Value of Separate Accounts by Major Category of Investment

The following table represents the fair value hierarchy for our cash equivalents and available-for-sale securities by major security type (in thousands):

	As of March 31, 2019
	Level 1		Level 2		Level 3		Total
Cash and money market funds	$	23,021	$	—	$	—	$	23,021
U.S. Treasury securities		38,996		—		—		38,996
Corporate debt securities		—		42,636		—		42,636
Total	$	62,017	$	42,636	$	—	$	104,653

	As of December 31, 2018
	Level 1		Level 2		Level 3		Total
Cash and money market funds	$	30,411	$	—	$	—	$	30,411
U.S. Treasury securities		42,184		—		—		42,184
Corporate debt securities		—		38,654		—		38,654
Total	$	72,595	$	38,654	$	—	$	111,249