Fair Value (Financial Assets and Liabilities, Not Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	$ 679	$ 643
Debt Securities, Held-to-maturity	696	641
Debt and other financing obligations, carrying value	56,756	44,632
Long-term debt and other financing obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations, carrying value	56,823	46,003
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	679	643
Fair Value, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	577	534
Fair Value, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	102	102
Fair Value, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	0	7
Long-term debt and other financing obligations [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations	53,626	52,583
Long-term debt and other financing obligations [Member] | Fair Value, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations	0	0
Long-term debt and other financing obligations [Member] | Fair Value, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations	53,626	52,583
Long-term debt and other financing obligations [Member] | Fair Value, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations	$ 0	$ 0