Temporarily Impaired Available for Sale Debt Securities by Time Period Impaired (Details) - USD ($) $ in Thousands	Sep. 24, 2022	Dec. 25, 2021
Debt Securities, Available-for-sale [Line Items]
Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 5,499,697	$ 4,242,438
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	427,306	73,221
Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	3,094,972	1,131,942
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	458,805	36,044
Unrealized Loss Position, Fair Value	8,594,669	5,374,380
Unrealized Loss Position, Accumulated Loss	886,111	109,265
Taxable bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	5,240,412	4,225,323
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	422,826	72,862
Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	3,094,972	1,131,942
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	458,805	36,044
Unrealized Loss Position, Fair Value	8,335,384	5,357,265
Unrealized Loss Position, Accumulated Loss	881,631	108,906
Tax exempt bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	92,896	0
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	669	0
Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	0	0
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Unrealized Loss Position, Fair Value	92,896	0
Unrealized Loss Position, Accumulated Loss	669	0
Restricted investments [Member]
Debt Securities, Available-for-sale [Line Items]
Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	166,389	17,115
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	3,811	359
Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	0	0
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	0	0
Unrealized Loss Position, Fair Value	166,389	17,115
Unrealized Loss Position, Accumulated Loss	$ 3,811	$ 359