Note 4 – Investments

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									767
Total carrying value of available-for-sale investments								$	219,290

At December 31, 2015, 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	$	11,325	$	1,575	$	(66	)	$	12,834
Corporate bonds		58,328		20		(734	)		57,614
Municipal fixed-rate bonds		26,414		28		(18	)		26,424
Asset-backed bonds		19,281		2		(44	)		19,239
Mortgage/Agency-backed bonds		15,463		1		(91	)		15,373
Government bonds		35,646		—		(248	)		35,398
Marketable equity securities		31,643		4,301		(1,693	)		34,251
Available-for-sale securities held at fair value	$	198,100	$	5,927	$	(2,894	)	$	201,133
Restricted investment held at cost									30,000
Other investments held at cost									1,289
Total carrying value of available-for-sale investments								$	232,422

As of December 31, 2016, 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	$	18,912	$	8,321	$	—	$	—	$	1,701	$	2,400
One to two years		32,497		1,703		635		976		4,903		1,330
Two to three years		11,486		351		2,415		980		13,072		—
Three to five years		3,517		1,399		5,402		—		10,091		—
Five to ten years		—		—		1,600		2,060		—		—
More than ten years		—		—		154		8,988		—		—
Total	$	66,412	$	11,774	$	10,206	$	13,004	$	29,767	$	3,730

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, 2016, 2015 and 2014, we recorded a charge of $0.8 million, $0.2 million and $0.1 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, 2016, 2015 and 2014:

Year Ended December 31,

(In thousands)

2016

2015

2014

Gross realized gains

7,530

10,906

7,586

Gross realized losses

(1,607

)

(569

)

(308

)

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 following table presents the breakdown of investments with unrealized losses at December 31, 2015:

(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	$	1,243	$	(53	)	$	92	$	(13	)	$	1,335	$	(66	)
Corporate bonds		35,952		(566	)		3,042		(168	)		38,994		(734	)
Municipal fixed-rate bonds		9,160		(18	)		—		—			9,160		(18	)
Asset-backed bonds		16,857		(44	)		—		—			16,857		(44	)
Mortgage/Agency-backed bonds		15,216		(91	)		—		—			15,216		(91	)
Government bonds		35,397		(248	)		—		—			35,397		(248	)
Marketable equity securities		14,364		(1,564	)		374		(129	)		14,738		(1,693	)
Total	$	128,189	$	(2,584	)	$	3,508	$	(310	)	$	131,697	$	(2,894	)

The decrease in unrealized losses during 2016, as reflected in the table above, results from changes in market positions associated with our fixed income and equity investment portfolio. At December 31, 2016, a total of 293 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, 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 – technology industry		3,374		3,374		—		—
Marketable equity securities – other		26,005		26,005		—		—
Available-for-sale securities		190,723		73,742		116,981		—
Total	$	214,823	$	80,620	$	134,203	$	—
	Fair Value Measurements at December 31, 2015 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	$	1,271	$	1,271	$	—	$	—
Commercial paper		11,696		—		11,696		—
Cash equivalents		12,967		1,271		11,696		—
Available-for-sale securities
Deferred compensation plan assets		12,834		12,834		—		—
Available-for-sale debt securities
Corporate bonds		57,614		—		57,614		—
Municipal fixed-rate bonds		26,424		—		26,424		—
Asset-backed bonds		19,239		—		19,239		—
Mortgage/Agency-backed bonds		15,373		—		15,373		—
Government bonds		35,398		35,398		—		—
Available-for-sale marketable equity securities
Marketable equity securities – technology industry		5,384		5,384		—		—
Marketable equity securities – other		28,867		28,867		—		—
Available-for-sale securities		201,133		82,483		118,650		—
Total	$	214,100	$	83,754	$	130,346	$	—

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.