(3) Investments


(a)	Debt Securities

Following is a summary of debt securities as of December 28, 2019 and December 29, 2018:



	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(Amounts are in thousands)
2019
Tax exempt bonds	$	767,931		3,429		130	771,230
Taxable bonds	5,002,036			120,132		1,443	5,120,725
Restricted investments	169,983			10,101		—	180,084
	$	5,939,950		133,662		1,573	6,072,039
2018
Tax exempt bonds	$	1,256,673		184		12,759	1,244,098
Taxable bonds	2,527,468			1,737		55,085	2,474,120
Restricted investment	160,318			520		346	160,492
	$	3,944,459		2,441		68,190	3,878,710

The Company maintains restricted investments primarily for the benefit of the Company’s insurance carrier related to self-insurance reserves. These investments are held as collateral and not used for claim payments.

The cost and fair value of debt securities by expected maturity as of December 28, 2019 and December 29, 2018 are as follows:



	2019			2018
	Cost		Fair Value	Cost	Fair Value
			(Amounts are in thousands)
Due in one year or less	$	437,236	438,105	563,272	560,992
Due after one year through five years	3,836,333		3,900,904	2,831,916	2,768,971
Due after five years through ten years	1,661,143		1,727,594	542,488	541,852
Due after ten years	5,238		5,436	6,783	6,895
	$	5,939,950	6,072,039	3,944,459	3,878,710

Following is a summary of temporarily impaired debt securities by the time period impaired as of December 28, 2019 and December 29, 2018:



	Less Than 12 Months				12 Months or Longer			Total
	Fair Value		Unrealized Losses		Fair Value	Unrealized Losses		Fair Value	Unrealized Losses
	(Amounts are in thousands)
2019
Tax exempt bonds	$	48,462		11	99,976		119	148,438		130
Taxable bonds	573,315			888	197,641		555	770,956		1,443
	$	621,777		899	297,617		674	919,394		1,573
2018
Tax exempt bonds	$	25,150		95	1,182,783		12,664	1,207,933		12,759
Taxable bonds	645,379			5,821	1,464,208		49,264	2,109,587		55,085
Restricted investment	28,687			346	—		—	28,687		346
	$	699,216		6,262	2,646,991		61,928	3,346,207		68,190

There are 80 debt securities contributing to the total unrealized losses of $1,573,000 as of December 28, 2019. Unrealized losses related to debt securities are primarily due to increases in interest rates that occurred since the debt securities were purchased. The Company continues to receive scheduled principal and interest payments on these debt securities.


(b)	Equity Securities

The fair value of equity securities was $2,354,346,000 and $2,698,720,000 as of December 28, 2019 and December 29, 2018, respectively.


(c)	Investment Income

Net realized gain on the sale of investments represents the difference between the cost and the proceeds from the sale of debt and equity securities. For 2019 and 2018, the net realized gain on the sale of investments excludes the net gain or loss on the sale of equity securities previously recognized through the fair value adjustment, which is presented separately in the following table.

Following is a summary of investment income for 2019, 2018 and 2017:



	2019			2018			2017
	(Amounts are in thousands)
Interest and dividend income		$	186,748		129,953			117,702
Net realized gain on sale of investments		104,905			109,547			108,924
		291,653			239,500			226,626
Fair value adjustment, due to net unrealized gain (loss), on equity securities held at end of year		472,490			(107,466	)		—
Net loss (gain) on sale of equity securities previously recognized through fair value adjustment		50,229			(75,335	)		—
		$	814,372		56,699			226,626