Cash, Cash Equivalents and Investments (Tables)

9 Months Ended

Sep. 30, 2019

Cash and Cash Equivalents [Abstract]

Summary of Cash, Cash Equivalents and Held-to-Maturity Investments by Type

The following tables summarize our cash, cash equivalents, and held-to-maturity investments at September 30, 2019 and December 31, 2018 (in thousands):

	As of September 30, 2019
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Cash and Cash Equivalents		Short-Term Investments		Long-Term Investments
Cash	$	80,269	$	—	$	—		$	80,269	$	80,269	$	—	$	—
Level 1:
Money market funds	37,311		—		—			37,311		37,311		—		—
Agency bonds	32,834		4		(6		)	32,832		12,068		2,000		18,766
Subtotal	70,145		4		(6		)	70,143		49,379		2,000		18,766
Level 2:
State and municipal obligations	4,454		1		(1		)	4,454		—		4,454		—
Corporate bonds	127,987		51		(31		)	128,007		2,903		102,459		22,625
U.S. Treasury repurchase agreements	70,000		—		—			70,000		70,000		—		—
Subtotal	202,441		52		(32		)	202,461		72,903		106,913		22,625
Total	$	352,855	$	56	$	(38	)	$	352,873	$	202,551	$	108,913	$	41,391

	As of December 31, 2018
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value		Cash and Cash Equivalents		Short-Term Investments		Long-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	$	—	$	—