Fair Value Measurements and Available for Sale Investments (Tables)

3 Months Ended

Mar. 31, 2020

Fair Value Measurements And Available For Sale Investments [Abstract]

Assets Measured at Fair Value on Recurring Basis

The following table presents the hierarchy for assets measured at fair value on a recurring basis as of March 31, 2020 and December 31, 2019 (in thousands):

	Fair Value Measurements at End of Period Using:
				Quoted Market		Significant		Significant
				Prices for		Other Observable		Unobservable
		Total		Identical Assets		Inputs		Inputs
		Fair Value		(Level 1)		(Level 2)		(Level 3)
As of March 31, 2020
Money market funds		$	31,488	$	31,488	$	—	$	—
U.S. Treasury and agency securities			25,700		25,700		—		—
Commercial paper			71,961		—		71,961		—
Corporate debt securities			153,121		—		153,121		—
As of December 31, 2019
Money market funds		$	82,125	$	82,125	$	—	$	—
U.S. Treasury and agency securities			91,717		91,717		—		—
Commercial paper			37,411		—		37,411		—
Corporate debt securities			156,277		—		156,277		—

Schedule of Available for Sale Investments by Security Type

The aggregate market value, cost basis, and gross unrealized gains and losses of available-for-sale investments by security type, classified in marketable securities and long-term investments as of March 31, 2020 are as follows (in thousands):

			Gross		Gross
	Amortized		Unrealized		Unrealized			Total
	Cost		Gains		Losses			Fair Value
Marketable securities
U.S. Treasury and agency securities	$	25,629	$	71	$	—		$	25,700
Commercial paper		55,991		—		—			55,991
Corporate debt securities		153,592		103		(574	)		153,121
Total marketable securities	$	235,212	$	174	$	(574	)	$	234,812

Schedule of Contractual Maturities of Available-for-sale Debt Securities

Contractual maturities of available-for-sale debt securities, as of March 31, 2020, were as follows (in thousands):

	Estimated
	Fair Value
Due within one year	$	203,072
One to two years		31,740
Total	$	234,812