Investments (Tables)

9 Months Ended

Sep. 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 September 26, 2020 and December 28, 2019:

	Cost		Gross Unrealized Gains	Gross Unrealized Losses	Fair Value
	(Amounts are in thousands)
September 26, 2020
Tax exempt bonds	$	596,669	9,110	136	605,643
Taxable bonds	7,478,037		276,735	7,898	7,746,874
Restricted investments	167,603		15,659	—	183,262
	$	8,242,309	301,504	8,034	8,535,779
December 28, 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 September 26, 2020 and December 28, 2019 are as follows:

			September 26, 2020			December 28, 2019
	Cost			Fair Value	Cost		Fair Value
	(Amounts are in thousands)
Due in one year or less	$	645,524		650,446	437,236		438,105
Due after one year through five years	5,089,321			5,277,428	3,836,333		3,900,904
Due after five years through ten years	2,503,518			2,603,665	1,661,143		1,727,594
Due after ten years	3,946			4,240	5,238		5,436
	$	8,242,309		8,535,779	5,939,950		6,072,039

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 September 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)
September 26, 2020
Tax exempt bonds	$	29,415			136	—			—	29,415			136
Taxable bonds	1,420,268				7,898	—			—	1,420,268			7,898
	$	1,449,683			8,034	—			—	1,449,683			8,034
December 28, 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 the three and nine months ended September 26, 2020 and September 28, 2019:

		Three Months Ended					Nine Months Ended
	September 26, 2020			September 28, 2019		September 26, 2020		September 28, 2019
	(Amounts are in thousands)
Interest and dividend income		$	47,061		46,796		148,239		135,526
Net realized gain on investments		109,132			33,798		217,596		104,242
		156,193			80,594		365,835		239,768
Fair value adjustment, due to net unrealized gain (loss), on equity securities held at end of period		130,637			(26,936)		340,618		292,381
Net (gain) loss on sale of equity securities previously recognized through fair value adjustment		(21,535)			16,391		(97,540)		50,229
		$	265,295		70,049		608,913		582,378