Employee Benefit Plans (Schedule of Allocation of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	$ 63,323	$ 62,318
Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	11,394	10,246
Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	21,178	23,065
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	1,885	1,649	$ 1,671
Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	27,666	26,569
Global Equities [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	9,417	8,442
Global Equities [Member] | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	9,411	8,437
Global Equities [Member] | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	6	5
Global Equities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Global Equities [Member] | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Global Equity Commingled Funds [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	932	2,687
Global Equity Commingled Funds [Member] | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	3	1
Global Equity Commingled Funds [Member] | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	929	2,686
Global Equity Commingled Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Global Equity Commingled Funds [Member] | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Enhanced Global Equities [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	209	241
Enhanced Global Equities [Member] | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	46	56
Enhanced Global Equities [Member] | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	163	185
Enhanced Global Equities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Enhanced Global Equities [Member] | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Other Public Equities
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	8,495	9,008
Other Public Equities | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Other Public Equities | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Other Public Equities | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Other Public Equities | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	8,495	9,008
Private Equity Funds [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	4,490	3,646
Private Equity Funds [Member] | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Private Equity Funds [Member] | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Private Equity Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0	202
Private Equity Funds [Member] | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	4,490	3,646
Governments [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	3,105	3,220
Governments [Member] | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	1,933	1,740
Governments [Member] | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	1,172	1,480
Governments [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Governments [Member] | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Corporate Debt Securities [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	18,682	18,799
Corporate Debt Securities [Member] | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	1	3
Corporate Debt Securities [Member] | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	18,681	18,489
Corporate Debt Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	2	5
Corporate Debt Securities [Member] | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	305
Structured Products
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	25	24
Structured Products | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Structured Products | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	25	24
Structured Products | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Structured Products | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Fixed Income Securities [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	7,367	6,631
Fixed Income Securities [Member] | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Fixed Income Securities [Member] | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Fixed Income Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Fixed Income Securities [Member] | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	7,367	6,631
Real Estate [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	3,628	3,384
Real Estate [Member] | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Real Estate [Member] | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Real Estate [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	1,885	1,647	$ 1,464
Real Estate [Member] | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	1,743	1,737
Other Pension Plan Assets [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	5,442	5,187
Other Pension Plan Assets [Member] | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Other Pension Plan Assets [Member] | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	91	99
Other Pension Plan Assets [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Other Pension Plan Assets [Member] | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	5,351	5,088
Cash & Cash Equivalents [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	331	260
Cash & Cash Equivalents [Member] | Quoted price in active markets (Level 1) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	9
Cash & Cash Equivalents [Member] | Significant other observable inputs (Level 2) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	111	97
Cash & Cash Equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	0	0
Cash & Cash Equivalents [Member] | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	220	154
Pension Plan Assets Leveled [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	62,123	61,529
Other Assets And Liabilities [Member]
Defined Benefit Plan, Plan Assets, Allocation [Line Items]
Fair value of plan assets	$ 1,200	$ 789