Available-for-Sale-Securities (Tables)

6 Months Ended

Jun. 30, 2018

Available-for-sale Securities [Abstract]

Schedule of Available-for-sale Securities Reconciliation

The following table is a summary of available-for-sale securities recorded in cash and cash equivalents or marketable securities in our Consolidated Balance Sheets (in thousands):

	June 30, 2018									December 31, 2017
	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value		Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Corporate debt securities	$	34,276	$	—	$	(31	)	$	34,245	$	42,701	$	—	$	(28	)	$	42,673
Money market funds	5,730		—		—			5,730		9,212		—		—			9,212
Total	$	40,006	$	—	$	(31	)	$	39,975	$	51,913	$	—	$	(28	)	$	51,885

Schedule of Marketable Securities

Estimated fair values of available-for-sale securities are generally based on prices obtained from commercial pricing services. The following table summarizes the classification of the available-for-sale debt securities on our Consolidated Balance Sheets (in thousands):

	June 30, 2018		December 31, 2017
Cash and cash equivalents	$	12,378	$	25,968
Marketable securities	27,597		25,917
Total	$	39,975	$	51,885

Investments Classified by Contractual Maturity Date

The following table summarizes our portfolio of available-for-sale debt securities by contractual maturity (in thousands):

	June 30, 2018
	Amortized Cost		Estimated Fair Value
Less than one year	$	40,006	$	39,975
Greater than one year	—		—
Total	$	40,006	$	39,975