NOTE 6. INVESTMENTS

The following tables summarize the Company’s available-for-sale investments at June 30, 2017, and December 31, 2016:



AVAILABLE-FOR-SALE INVESTMENTS
June 30, 2017
(in thousands)
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Certificates of deposit	$	12,410	$	—	$	—		$	12,410
US Treasury securities	7,041		—		(16		)	7,025
US Agency securities	4,516		—		(17		)	4,499
Commercial paper	5,141		—		—			5,141
Asset-backed securities	5,027		—		(1		)	5,026
Corporate notes and bonds	38,547		—		(39		)	38,508
Total	$	72,682	$	—	$	(73	)	$	72,609



AVAILABLE-FOR-SALE INVESTMENTS
December 31, 2016
(in thousands)
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Certificates of deposit	$	7,257	$	—	$	—		$	7,257
US Treasury securities	8,553		1		(10		)	8,544
US Agency securities	4,514		—		(13		)	4,501
Asset-backed securities	5,554		3		—			5,557
Corporate notes and bonds	32,717		3		(60		)	32,660
Total	$	58,595	$	7	$	(83	)	$	58,519

The following table summarizes the maturities of the Company’s available-for-sale securities at June 30, 2017, and December 31, 2016:



AVAILABLE-FOR-SALE INVESTMENT MATURITIES
(in thousands)
	June 30, 2017				December 31, 2016
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in less than 1 year	$	57,292	$	57,246	$	45,391	$	45,344
Due in 1-5 years	15,390		15,363		13,204		13,175
Total	$	72,682	$	72,609	$	58,595	$	58,519

Proceeds from sales of marketable securities (including principal paydowns), for the three months ended June 30, 2017 and 2016 were $6.5 million and $500,000, respectively, and for the for the six months ended June 30, 2017 and 2016 were $6.5 million and $1.0 million, respectively. The Company determines gains and losses of marketable securities based on specific identification of the securities sold. There were no gross realized gains or losses from sales of marketable securities for the three and six months ended June 30, 2017 and 2016.

No other-than-temporary impairments are recorded as no material investment had a fair value that remained less than its cost for more than twelve months as of June 30, 2017, and there have been no other indicators of impairment. The Company does not intend to sell investments and it is more likely than not that we will not be required to sell investments before recovering the amortized cost.

Additional information regarding the fair value of our financial instruments is included in Note 4, Fair Value of Financial Instruments.