Investments (Tables)

12 Months Ended

Dec. 26, 2020

Investments, Debt and Equity Securities [Abstract]

Available For Sale Debt Securities [Table Text Block]

Following is a summary of debt securities as of December 26, 2020 and December 28, 2019:

	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(Amounts are in thousands)
2020
Tax exempt bonds	$	548,438		7,408		88	555,758
Taxable bonds	8,182,003			286,745		8,324	8,460,424
Restricted investments	167,727			14,383		—	182,110
	$	8,898,168		308,536		8,412	9,198,292
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

Amortized Cost and Fair Value of Available for Sale Debt Securities by Expected Maturity [Table Text Block]

The cost and fair value of debt securities by expected maturity as of December 26, 2020 and December 28, 2019 are as follows:

	2020			2019
	Cost		Fair Value	Cost	Fair Value
			(Amounts are in thousands)
Due in one year or less	$	677,453	682,965	437,236	438,105
Due after one year through five years	5,330,696		5,533,074	3,836,333	3,900,904
Due after five years through ten years	2,886,333		2,978,301	1,661,143	1,727,594
Due after ten years	3,686		3,952	5,238	5,436
	$	8,898,168	9,198,292	5,939,950	6,072,039

Temporarily Impaired Available for Sale Debt Securities by Time Period Impaired [Table Text Bock}

Following is a summary of debt securities with other unrealized losses by the time period impaired as of December 26, 2020 and December 28, 2019:

	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)
2020
Tax exempt bonds	$	3,704		88	—		—	3,704		88
Taxable bonds	1,157,387			7,946	39,622		378	1,197,009		8,324
	$	1,161,091		8,034	39,622		378	1,200,713		8,412
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

Investment Income [Table Text Block]

Following is a summary of investment income for 2020, 2019 and 2018:

	2020			2019		2018
	(Amounts are in thousands)
Interest and dividend income		$	199,435		186,748		129,953
Net realized gain on investments		396,584			104,905		109,547
		596,019			291,653		239,500
Fair value adjustment, due to net unrealized gain (loss), on equity securities held at end of year		554,547			472,490		(107,466)
Net (gain) loss on sale of equity securities previously recognized through fair value adjustment		(175,560)			50,229		(75,335)
		$	975,006		814,372		56,699