Note 3. Investments

Available-for-sale securities consist of fixed-income securities that are accounted for at fair value. Available-for-sale securities with an original maturity of 90 days or less are classified within cash and cash equivalents in the condensed consolidated balance sheets. Premiums and discounts paid on securities at the time of purchase are recorded as accrued interest and amortized over the period of maturity. As of June 30, 2017, the Company did not hold any investments with a maturity date greater than one year. The amortized cost and fair value on the available-for-sale investments and unrealized gains and losses as of June 30, 2017 and December 31, 2016 were as follows (in thousands):

	June 30, 2017
	Amortized		Gross Unrealized		Gross Unrealized			Fair
	Cost		Gains		Losses			Value
Amounts with an original maturity of 90 days or less
Corporate notes and obligations	$	2,498	$	—	$	—		$	2,498
U.S. agency securities		4,492		—		—			4,492
Total short-term available-for-sale debt securities classified as cash and cash equivalents	$	6,990	$	—	$	—		$	6,990

Amounts maturing in one year or less
Corporate notes and obligations	$	35,229	$	—	$	(23	)	$	35,206
U.S. government treasury securities		49,193		—		(124	)		49,069
Total short-term available-for-sale debt securities classified as investments	$	84,422	$	—	$	(147	)	$	84,275

	December 31, 2016
	Amortized		Gross Unrealized		Gross Unrealized			Fair
	Cost		Gains		Losses			Value
Amounts maturing in one year or less
Corporate notes and obligations	$	29,866	$	—	$	(25	)	$	29,841
U.S. government treasury securities		6,900		—		—			6,900
Total short-term available-for-sale debt securities	$	36,766	$	—	$	(25	)	$	36,741

Amounts maturing in greater than one year
Corporate notes and obligations	$	4,010	$	—	$	(11	)	$	3,999
U.S. government treasury securities		34,505		—		(58	)		34,447
Total long-term available-for-sale debt securities	$	38,515	$	—	$	(69	)	$	38,446

As of June 30, 2017 and December 31, 2016, the Company did not consider any of the unrealized losses on its investments to be other-than-temporarily impaired based on its evaluation of available evidence. None of the investments held as of June 30, 2017 and December 31, 2016 have been in a continuous unrealized loss position for more than 12 months. Realized gains and losses on sales of available-for-sale securities were immaterial for both periods presented.