Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2017

Schedule of available-for-sale securities


	September 30, 2017								December 31, 2016
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized (Loss)		Estimated Fair Value		Amortized Cost		Gross Unrealized Gain		Gross Unrealized (Loss)		Estimated Fair Value
	(in thousands)
Money market deposits	$	286	$	—	$	—	$	286	$	10,777	$	—	$	—	$	10,777
U.S. Treasury securities		84,550		8		(279)		84,279		57,846		—		(404)		57,442
U.S. agency securities		39,106		—		(136)		38,970		56,261		—		(147)		56,114
Municipal securities		11,757		15		(4)		11,768		17,478		—		(174)		17,304
Total	$	135,699	$	23	$	(419)	$	135,303	$	142,362	$	—	$	(725)	$	141,637

Classified as:
Cash equivalents							$	286							$	10,777
Short-term investments								135,017								130,860
Total							$	135,303							$	141,637

Summarized portfolio of available-for-sale securities by contractual maturity


	September 30, 2017
	Amortized Cost		Fair Value
	(in thousands)
Less than one year	$	86,061	$	85,999
Greater than one year but less than five years		49,352		49,018
Total	$	135,413	$	135,017

- Definition

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

+ References + Details