Short-Term Investments (Tables)

3 Months Ended

Mar. 31, 2019

Investments Disclosure [Abstract]

Summary of Investments Included in Cash Equivalents and Short Term Investments

The following table summarizes the Company’s investments, which are included in cash equivalents and short-term investments:

As of March 31, 2019	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Money market mutual funds	$	40,291	$	—	$	—		$	40,291
Asset-backed securities		18,078		2		(1	)		18,079
Commercial paper		56,350		—		—			56,350
Corporate debt securities		45,887		6		(9	)		45,884
U.S. Treasury securities		26,876		8		—			26,884
Total	$	187,482	$	16	$	(10	)	$	187,488
As of December 31, 2018	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
	(in thousands)
Money market mutual funds	$	31,740	$	—	$	—		$	31,740
Asset-backed securities		19,541		—		(21	)		19,520
Commercial paper		78,571		—		—			78,571
Corporate debt securities		54,511		—		(50	)		54,461
U.S. Treasury securities		29,980		—		(6	)		29,974
Total	$	214,343	$	—	$	(77	)	$	214,266