NOTE 6. INVESTMENTS

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



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Certificates of deposit	$	13,936	$	—	$	—		$	13,936
U.S. Treasury securities	18,963		—		(100		)	18,863
U.S. Agency securities	7,006		—		(65		)	6,941
Commercial paper	2,791		—		—			2,791
Asset-backed securities	—		—		—			—
Corporate notes and bonds	24,305		—		(82		)	24,223
Total	$	67,001	$	—	$	(247	)	$	66,754



	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 March 31, 2018 and December 31, 2017 (in thousands):



	March 31, 2018				December 31, 2017
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due in less than 1 year	$	40,973	$	40,864	$	55,801	$	55,735
Due in 1-5 years	26,028		25,890		25,040		24,913
Total	$	67,001	$	66,754	$	80,841	$	80,648

Proceeds from sales of marketable securities (including principal paydowns) for the three months ended March 31, 2018 and 2017, were $3.0 million and $0, 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 months ended March 31, 2018 and 2017. No balances were reclassified out of accumulated other comprehensive income (loss) for the three months ended March 31, 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.