(8) Investments

Investments include primarily investment-grade corporate bonds and U.S. Treasury obligations having maturities of up to five years (the “bond portfolio”). Investments in the bond portfolio are reported as available-for-sale and are carried at fair value. Investments maturing less than one year from the balance sheet date are included in short-term investments and investments maturing more than one year from the balance sheet date are included in other assets in the consolidated balance sheets. Management performs an analysis of the nature of the unrealized losses on available-for-sale investments to determine whether such losses are other-than-temporary. Unrealized losses, representing the excess of the purchase price of an investment over its fair value as of the end of a period, considered to be other-than-temporary, are to be included as a charge in the statement of income, while unrealized losses considered to be temporary are to be included as a component of equity. Investments whose values are based on quoted market prices in active markets are classified within Level 1. Investments that trade in markets that are not considered to be active, but are valued based on quoted market prices, are classified within Level 2. As Level 2 investments include positions that are not traded in active markets, valuations may be adjusted to reflect illiquidity and/or non-transferability, which are generally based on available market information. Any transfers between levels are recognized as of the beginning of any reporting period. Fair value of the bond portfolio was determined using Level 1 inputs related to U.S. Treasury obligations and money market investments and Level 2 inputs related to investment-grade corporate bonds, asset-backed securities and direct obligations of government agencies. Unrealized gains, net of unrealized losses, on the investments in the bond portfolio were $278,000 at September 30, 2017, while unrealized losses, net of unrealized gains, on the investments in the bond portfolio were $109,000 at December 31, 2016, respectively.

The amortized cost and fair values of available-for-sale investments are as follows at September 30, 2017 and December 31, 2016 (in thousands):


	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
September 30, 2017
Money market investments	$	16,823	$	—	$	—	$	16,823
Asset-backed securities		3,497		2		5		3,494
Corporate bonds and direct obligations of government agencies		84,885		373		91		85,167
U.S. Treasury obligations		5,496		—		1		5,495

Total	$	110,701	$	375	$	97	$	110,979


December 31, 2016
Money market investments	$	12,395	$	—	$	—	$	12,395
Asset-backed securities		4,027		3		19		4,011
Corporate bonds and direct obligations of government agencies		70,069		150		239		69,980
U.S. Treasury obligations		23,037		2		6		23,033

Total	$	109,528	$	155	$	264	$	109,419

For those available-for-sale investments with unrealized losses at September 30, 2017 and December 31, 2016, the following table summarizes the duration of the unrealized loss (in thousands):


	Less than 12 months				12 months or longer						Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
September 30, 2017
Asset-backed securities	$	—	$	—	$	2,311	$	5	$	2,311	$	5
Corporate bonds and direct obligations of government agencies		15,429		21		13,215		70		28,644		91
U.S. Treasury obligations		5,495		1		—		—		5,495		1

Total	$	20,924	$	22	$	15,526	$	75	$	36,450	$	97


December 31, 2016
Asset-backed securities	$	1,363	$	6	$	2,314	$	13	$	3,677	$	19
Corporate bonds and direct obligations of government agencies		28,809		195		1,367		44		30,176		239
U.S. Treasury obligations		12,734		6		—		—		12,734		6

Total	$	42,906	$	207	$	3,681	$	57	$	46,587	$	264

The Company expects to recover the amortized cost basis of these securities as it does not intend to sell, and does not anticipate being required to sell, these securities before recovery of the cost basis. For these reasons, the Company does not consider the unrealized losses on these securities to be other-than-temporary at September 30, 2017.