Temporarily Impaired Available for Sale Debt Securities by Time Period Impaired (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 25, 2021
Debt Securities, Available-for-sale [Line Items]
Continuous Unrealized Loss Position, Less than 12 Months	$ 3,856	$ 4,242
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	201	73
Continuous Unrealized Loss Position, 12 Months or Longer	4,642	1,132
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	633	36
Debt Securities, Unrealized Loss Position	8,498	5,374
Debt Securities, Unrealized Loss Position, Accumulated Loss	834	109
Taxable Bonds
Debt Securities, Available-for-sale [Line Items]
Continuous Unrealized Loss Position, Less than 12 Months	3,705	4,225
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	199	72
Continuous Unrealized Loss Position, 12 Months or Longer	4,627	1,132
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	631	36
Debt Securities, Unrealized Loss Position	8,332	5,357
Debt Securities, Unrealized Loss Position, Accumulated Loss	830	108
Restricted Investments
Debt Securities, Available-for-sale [Line Items]
Continuous Unrealized Loss Position, Less than 12 Months	151	17
Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2	1
Continuous Unrealized Loss Position, 12 Months or Longer	15	0
Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	2	0
Debt Securities, Unrealized Loss Position	166	17
Debt Securities, Unrealized Loss Position, Accumulated Loss	$ 4	$ 1