Cash, Cash Equivalents and Investments (Tables)

12 Months Ended

Dec. 31, 2017

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 December 31, 2017 and December 31, 2016 (in thousands):

	As of December 31, 2017
	Amortized Cost		Gross Unrealized Losses			Fair Value		Cash and Cash Equivalents		Short-Term Investments		Long-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	$	—

	As of December 31, 2016
	Amortized Cost		Gross Unrealized Losses			Fair Value		Cash and Cash Equivalents		Short-Term Investments		Long-Term Investments
Cash	$	32,802	$	—		$	32,802	$	32,802	$	—	$	—
Level 1:
Money market funds	7,849		—			7,849		7,849		—		—
Corporate bonds	33,379		(57		)	33,322		—		33,379		—
Subtotal	41,228		(57		)	41,171		7,849		33,379		—
Level 2:
State and municipal obligations	14,477		(10		)	14,467		—		14,243		234
Certificates of deposit	793		—			793		—		793		—
Subtotal	15,270		(10		)	15,260		—		15,036		234
Total	$	89,300	$	(67	)	$	89,233	$	40,651	$	48,415	$	234