Investments (Tables)

6 Months Ended

Jun. 26, 2021

Investments, Debt and Equity Securities [Abstract]

Available For Sale Debt Securities [Table Text Block]

Following is a summary of debt securities as of June 26, 2021 and December 26, 2020:

	Cost		Gross Unrealized Gains	Gross Unrealized Losses	Fair Value
	(Amounts are in thousands)
June 26, 2021
Tax exempt bonds	$	419,677	4,400	17	424,060
Taxable bonds	8,653,710		195,639	44,498	8,804,851
Restricted investments	170,648		11,334	101	181,881
	$	9,244,035	211,373	44,616	9,410,792
December 26, 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

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 June 26, 2021 and December 26, 2020 are as follows:

			June 26, 2021			December 26, 2020
	Cost			Fair Value	Cost		Fair Value
	(Amounts are in thousands)
Due in one year or less	$	672,427		678,075	677,453		682,965
Due after one year through five years	5,493,203			5,661,467	5,330,696		5,533,074
Due after five years through ten years	3,075,170			3,067,810	2,886,333		2,978,301
Due after ten years	3,235			3,440	3,686		3,952
	$	9,244,035		9,410,792	8,898,168		9,198,292

Available For Sale Debt Securities in an Unrealized Loss Position by Time Period Impaired [Table Text Block]

Following is a summary of debt securities with other unrealized losses by the time period impaired as of June 26, 2021 and December 26, 2020:

			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)
June 26, 2021
Tax exempt bonds	$	56,890			17	—			—	56,890			17
Taxable bonds	2,973,436				43,941	64,401			557	3,037,837			44,498
Restricted investments	9,793				101	—			—	9,793			101
	$	3,040,119			44,059	64,401			557	3,104,520			44,616
December 26, 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

Investment Income (Loss) [Table Text Block]

Following is a summary of investment income for the three and six months ended June 26, 2021 and June 27, 2020:

		Three Months Ended					Six Months Ended
	June 26, 2021			June 27, 2020		June 26, 2021		June 27, 2020
	(Amounts are in thousands)
Interest and dividend income		$	45,956		46,910		94,626		101,178
Net realized gain on investments		16,496			106,150		23,985		108,464
		62,452			153,060		118,611		209,642
Fair value adjustment, due to net unrealized gain, on equity securities held at end of period		128,961			597,408		913,811		209,981
Net gain on sale of equity securities previously recognized through fair value adjustment		(9,441)			(76,005)		(9,441)		(76,005)
		$	181,972		674,463		1,022,981		343,618