Cash, Cash Equivalents and Investments

3 Months Ended

Mar. 31, 2019

Cash and Cash Equivalents [Abstract]

Cash, Cash Equivalents and Investments

Cash, Cash Equivalents and Investments

The following tables summarize our cash, cash equivalents, and held-to-maturity investments at March 31, 2019 and December 31, 2018 (in thousands):

	As of March 31, 2019
	Amortized Cost		Gross Unrealized Losses			Fair Value		Cash and Cash Equivalents		Short-Term Investments
Cash	$	123,098	$	—		$	123,098	$	123,098	$	—
Level 1:
Money market funds	83,449		—			83,449		83,449		—
Level 2:
Corporate bonds	122,407		(56		)	122,351		17,095		105,312
Total	$	328,954	$	(56	)	$	328,898	$	223,642	$	105,312

	As of December 31, 2018
	Amortized Cost		Gross Unrealized Losses		Fair Value		Cash and Cash Equivalents		Short-Term Investments
Cash	$	144,095	$	—	$	144,095	$	144,095	$	—
Level 1:
Money market funds	205,367		—		205,367		205,367		—
Total	$	349,462	$	—	$	349,462	$	349,462	$	—

We believe unrealized losses on our investments are due to interest rate fluctuations. As these investments are short-term in nature, are expected to be redeemed at par value, and/or because we have the ability and intent to hold these investments to maturity, we do not consider these investments to be other than temporarily impaired as of March 31, 2019.