Note 4 – Investments

At December 31, 2017, we held the following securities and investments, recorded at either fair value or cost:

								Fair Value /
	Amortized		Gross Unrealized					Carrying
(In thousands)	Cost		Gains		Losses			Value
Deferred compensation plan assets	$	17,804	$	2,175	$	(96	)	$	19,883
Corporate bonds		32,654		44		(155	)		32,543
Municipal fixed-rate bonds		2,902		2		(22	)		2,882
Asset-backed bonds		6,545		1		(20	)		6,526
Mortgage/Agency-backed bonds		5,554		1		(46	)		5,509
U.S. government bonds		14,477		—		(174	)		14,303
Foreign government bonds		725		5		—			730
Marketable equity securities		33,478		3,034		(850	)		35,662
Available-for-sale securities held at fair value	$	114,139	$	5,262	$	(1,363	)	$	118,038
Restricted investment held at cost									27,800
Other investments									547
Total carrying value of available-for-sale investments								$	146,385

At December 31, 2016, we held the following securities and investments, recorded at either fair value or cost:

								Fair Value /
	Amortized		Gross Unrealized					Carrying
(In thousands)	Cost		Gains		Losses			Value
Deferred compensation plan assets	$	12,367	$	2,271	$	(42	)	$	14,596
Corporate bonds		66,522		64		(174	)		66,412
Municipal fixed-rate bonds		11,799		12		(37	)		11,774
Asset-backed bonds		10,201		19		(14	)		10,206
Mortgage/Agency-backed bonds		13,080		15		(91	)		13,004
U.S. government bonds		30,022		15		(270	)		29,767
Foreign government bonds		3,729		2		(1	)		3,730
Variable rate demand notes		11,855		—		—			11,855
Marketable equity securities		30,571		311		(1,503	)		29,379
Available-for-sale securities held at fair value	$	190,146	$	2,709	$	(2,132	)	$	190,723
Restricted investment held at cost									27,800
Other investments held at cost									767
Total carrying value of available-for-sale investments								$	219,290

As of December 31, 2017, corporate bonds, municipal fixed-rate bonds, asset-backed bonds, mortgage/agency-backed bonds, U.S. government bonds, and foreign government bonds had the following contractual maturities:

(In thousands)	Corporate bonds		Municipal fixed-rate bonds		Asset-backed bonds		Mortgage / Agency-backed bonds		U.S. government bonds		Foreign government bonds
Less than one year	$	12,021	$	891	$	143	$	—	$	3,073	$	—
One to two years		9,145		826		2,367		—		5,960		—
Two to three years		7,345		212		2,245		—		3,568		730
Three to five years		4,032		953		810		356		1,702		—
Five to ten years		—		—		158		1,144		—		—
More than ten years		—		—		803		4,009		—		—
Total	$	32,543	$	2,882	$	6,526	$	5,509	$	14,303	$	730

Our investment policy provides limitations for issuer concentration, which limits, at the time of purchase, the concentration in any one issuer to 5% of the market value of our total investment portfolio.

We review our investment portfolio for potential “other-than-temporary” declines in value on an individual investment basis. We assess, on a quarterly basis, significant declines in value which may be considered other-than-temporary and, if necessary, recognize and record the appropriate charge to write-down the carrying value of such investments. In making this assessment, we take into consideration qualitative and quantitative information, including but not limited to the following: the magnitude and duration of historical declines in market prices, credit rating activity, assessments of liquidity, public filings, and statements made by the issuer. We generally begin our identification of potential other-than-temporary impairments by reviewing any security with a fair value that has declined from its original or adjusted cost basis by 25% or more for six or more consecutive months. We then evaluate the individual security based on the previously identified factors to determine the amount of the write-down, if any. For each of the years ended December 31, 2017, 2016 and 2015, we recorded a charge of $0.2 million, $0.8 million and $0.2 million, respectively, related to the other-than-temporary impairment of certain marketable equity securities and our deferred compensation plan assets.

Realized gains and losses on sales of securities are computed under the specific identification method. The following table presents gross realized gains and losses related to our investments for the years ended December 31, 2017, 2016 and 2015:

Year Ended December 31,

(In thousands)

2017

2016

2015

Gross realized gains

5,258

7,530

10,906

Gross realized losses

(573

)

(1,607

)

(569

)

The following table presents the breakdown of investments with unrealized losses at December 31, 2017:

(In thousands)	Continuous Unrealized Loss Position for Less than 12 Months					Continuous Unrealized Loss Position for 12 Months or Greater					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Deferred compensation plan assets	$	1,922	$	(81	)	$	262	$	(15	)	$	2,184	$	(96	)
Corporate bonds		16,015		(58	)		6,112		(97	)		22,127		(155	)
Municipal fixed-rate bonds		230		—			1,165		(22	)		1,395		(22	)
Asset-backed bonds		4,941		(17	)		179		(3	)		5,120		(20	)
Mortgage/Agency-backed bonds		3,062		(8	)		1,673		(38	)		4,735		(46	)
U.S. government bonds		2,754		(26	)		11,549		(148	)		14,303		(174	)
Marketable equity securities		10,169		(712	)		544		(138	)		10,713		(850	)
Total	$	39,093	$	(902	)	$	21,484	$	(461	)	$	60,577	$	(1,363	)

The following table presents the breakdown of investments with unrealized losses at December 31, 2016:

(In thousands)	Continuous Unrealized Loss Position for Less than 12 Months					Continuous Unrealized Loss Position for 12 Months or Greater					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Deferred compensation plan assets	$	294	$	(12	)	$	245	$	(30	)	$	539	$	(42	)
Corporate bonds		32,562		(166	)		2,722		(8	)		35,284		(174	)
Municipal fixed-rate bonds		8,936		(37	)		—		—			8,936		(37	)
Asset-backed bonds		2,986		(14	)		—		—			2,986		(14	)
Mortgage/Agency-backed bonds		7,842		(81	)		1,239		(10	)		9,081		(91	)
U.S. government bonds		26,449		(270	)		—		—			26,449		(270	)
Foreign government bonds		924		(1	)		—		—			924		(1	)
Marketable equity securities		21,607		(1,200	)		1,495		(303	)		23,102		(1,503	)
Total	$	101,600	$	(1,781	)	$	5,701	$	(351	)	$	107,301	$	(2,132	)

The decrease in unrealized losses during 2017, as reflected in the table above, results from changes in market positions associated with our fixed income and equity investment portfolio. At December 31, 2017, a total of 274 of our marketable equity securities were in an unrealized loss position.

We have categorized our cash equivalents and our investments held at fair value into a three-level fair value hierarchy based on the priority of the inputs to the valuation technique for the cash equivalents and investments as follows: Level 1 - Values based on unadjusted quoted prices for identical assets or liabilities in an active market; Level 2 - Values based on quoted prices in markets that are not active or model inputs that are observable either directly or indirectly; Level 3 - Values based on prices or valuation techniques that require inputs that are both unobservable and significant to the overall fair value measurement. These inputs could include information supplied by investees.

	Fair Value Measurements at December 31, 2017 Using
(In thousands)	Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents
Money market funds	$	5,851	$	5,851	$	—	$	—
Commercial paper		3,999		—		3,999		—
Cash equivalents		9,850		5,851		3,999		—
Available-for-sale securities
Deferred compensation plan assets		19,883		19,883		—		—
Available-for-sale debt securities
Corporate bonds		32,543		—		32,543		—
Municipal fixed-rate bonds		2,882		—		2,882		—
Asset-backed bonds		6,526		—		6,526		—
Mortgage/Agency-backed bonds		5,509		—		5,509		—
U.S. government bonds		14,303		14,303		—		—
Foreign government bonds		730		—		730		—
Available-for-sale marketable equity securities
Marketable equity securities – various industries		35,662		35,662		—		—
Available-for-sale securities		118,038		69,848		48,190		—
Total	$	127,888	$	75,699	$	52,189	$	—

	Fair Value Measurements at December 31, 2016 Using
(In thousands)	Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents
Money market funds	$	6,878	$	6,878	$	—	$	—
Commercial paper		17,222		—		17,222		—
Cash equivalents		24,100		6,878		17,222		—
Available-for-sale securities
Deferred compensation plan assets		14,596		14,596		—		—
Available-for-sale debt securities
Corporate bonds		66,412		—		66,412		—
Municipal fixed-rate bonds		11,774		—		11,774		—
Asset-backed bonds		10,206		—		10,206		—
Mortgage/Agency-backed bonds		13,004		—		13,004		—
U.S. government bonds		29,767		29,767		—		—
Foreign government bonds		3,730		—		3,730		—
Variable rate demand notes		11,855		—		11,855		—
Available-for-sale marketable equity securities
Marketable equity securities – various industries		29,379		29,379		—		—
Available-for-sale securities		190,723		73,742		116,981		—
Total	$	214,823	$	80,620	$	134,203	$	—

The fair value of our Level 2 securities is calculated using a weighted average market price for each security. Market prices are obtained from a variety of industry standard data providers, security master files from large financial institutions, and other third-party sources. These multiple market prices are used as inputs into a distribution-curve-based algorithm to determine the daily market value of each security.

Our municipal variable rate demand notes have a structure that implies a standard expected market price. The frequent interest rate resets make it reasonable to expect the price to stay at par. These securities are priced at the expected market price.