Temporarily Impaired Available for Sale Debt Securities by Time Period Impaired (Details) - USD ($) $ in Thousands	Jun. 25, 2022	Dec. 25, 2021
Debt Securities, Available-for-sale [Line Items]
Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	$ 7,109,935	$ 4,242,438
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	510,314	73,221
Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	1,772,380	1,131,942
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	219,580	36,044
Unrealized Loss Position, Fair Value	8,882,315	5,374,380
Unrealized Loss Position, Accumulated Loss	729,894	109,265
Taxable bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	6,896,368	4,225,323
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	509,148	72,862
Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	1,763,638	1,131,942
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	218,579	36,044
Unrealized Loss Position, Fair Value	8,660,006	5,357,265
Unrealized Loss Position, Accumulated Loss	727,727	108,906
Tax exempt bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	167,063	0
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	211	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	167,063	0
Unrealized Loss Position, Accumulated Loss	211	0
Restricted investments [Member]
Debt Securities, Available-for-sale [Line Items]
Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	46,504	17,115
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	955	359
Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	8,742	0
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	1,001	0
Unrealized Loss Position, Fair Value	55,246	17,115
Unrealized Loss Position, Accumulated Loss	$ 1,956	$ 359