Cash, Cash Equivalents and Investments (Tables)

3 Months Ended

Mar. 31, 2018

Cash and Cash Equivalents [Abstract]

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

The following tables summarize the Company's cash, cash equivalents, and held-to-maturity investments at March 31, 2018 and December 31, 2017 (in thousands):

	As of March 31, 2018
	Amortized Cost		Gross Unrealized Losses			Fair Value		Cash and Cash Equivalents		Short-Term Investments
Cash	$	68,207	$	—		$	68,207	$	68,207	$	—
Level 1:
Money market funds	22,282		—			22,282		22,282		—
Corporate bonds	4,974		(3		)	4,971		1,300		3,674
Subtotal	27,256		(3		)	27,253		23,582		3,674
Level 2:
State and municipal obligations	1,342		—			1,342		541		801
Total	$	96,805	$	(3	)	$	96,802	$	92,330	$	4,475

	As of December 31, 2017
	Amortized Cost		Gross Unrealized Losses			Fair Value		Cash and Cash Equivalents		Short-Term Investments
Cash	$	53,459	$	—		$	53,459	$	53,459	$	—
Level 1:
Money market funds	20,884		—			20,884		20,884		—
Corporate bonds	6,632		(6		)	6,626		—		6,632
Subtotal	27,516		(6		)	27,510		20,884		6,632
Level 2:
State and municipal obligations	992		—			992		762		230
Total	$	81,967	$	(6	)	$	81,961	$	75,105	$	6,862