NOTE 6. INVESTMENTS

The following tables summarize the Company’s available-for-sale investments at June 30, 2018 and December 31, 2017 (in thousands):



	June 30, 2018
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Certificates of deposit	$	13,682	$	—	$	—		$	13,682
U.S. Treasury securities	31,850		1		(107		)	31,744
U.S. Agency securities	7,013		—		(69		)	6,944
Commercial paper	35,917		—		—			35,917
Asset-backed securities	8,992		2		(1		)	8,993
Corporate notes and bonds	33,388		1		(75		)	33,314
Total	$	130,842	$	4	$	(252	)	$	130,594



	December 31, 2017
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Certificates of deposit	$	13,441	$	—	$	—		$	13,441
U.S. Treasury securities	14,787		—		(71		)	14,716
U.S. Agency securities	8,510		—		(51		)	8,459
Commercial paper	9,171		—		—			9,171
Asset-backed securities	3,026		—		(1		)	3,025
Corporate notes and bonds	31,906		—		(70		)	31,836
Total	$	80,841	$	—	$	(193	)	$	80,648

The following table summarizes the maturities of the Company’s available-for-sale securities at June 30, 2018 and December 31, 2017 (in thousands):



	June 30, 2018				December 31, 2017
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in less than 1 year	$	95,448	$	95,312	$	55,801	$	55,735
Due in 1-5 years	35,394		35,282		25,040		24,913
Total	$	130,842	$	130,594	$	80,841	$	80,648

Proceeds from sales of marketable securities (including principal paydowns), for the three months ended June 30, 2018 and 2017 were $0 and $6.5 million, respectively, and for the six months ended June 30, 2018 and 2017 were $3.0 million and $6.5 million, respectively. The Company determines gains and losses of marketable securities based on specific identification of the securities sold. There were no realized gains from sales of marketable securities for the three and six months June 30, 2018 and 2017. No balances were reclassified out of accumulated other comprehensive income (loss) for the three and six months June 30, 2018 and 2017.

No other-than-temporary impairments are recorded as no material investments had a fair value that remained less than its cost for more than twelve months as of those dates. 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.