Cash, Cash Equivalents and Investments (Tables)

12 Months Ended

Dec. 31, 2016

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 (in thousands):

	As of December 31, 2016
	Amortized Cost		Gross Unrealized Gains		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

	As of December 31, 2015
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Cash and Cash Equivalents		Short-Term Investments		Long-Term Investments
Cash	$	57,137	$	—	$	—		$	57,137	$	57,137	$	—	$	—
Level 1:
Money market funds	2,389		—		—			2,389		2,389		—		—
Corporate bonds	36,406		—		(70		)	36,336		—		35,677		729
Subtotal	38,795		—		(70		)	38,725		2,389		35,677		729
Level 2:
State and municipal obligations	19,002		11		(9		)	19,004		—		12,000		7,002
Certificates of deposit	3,371		—		—			3,371		—		2,577		794
Subtotal	22,373		11		(9		)	22,375		—		14,577		7,796
Total	$	118,305	$	11	$	(79	)	$	118,237	$	59,526	$	50,254	$	8,525

Summary of Amortized Cost and Fair Value of Short-term and Long-term Investments

The following table summarizes the amortized cost and fair value of the short-term and long-term investments held by the Company at December 31, 2016 by contractual maturity (in thousands):

	Amortized Cost		Fair Value
Due in less than one year	$	48,415	$	48,349
Due after one year, through two years	234		233
Due after two years	—		—
Total short-term and long-term investments	$	48,649	$	48,582