Employee Benefit Plans (Pension Plans) (Level 3 Significant Unobservable Inputs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Beginning Balance, Plan Assets	$ 62,318
Ending Balance, Plan Assets	63,323	$ 62,318
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Beginning Balance, Plan Assets	1,649	1,671
Realized gains	212	7
Unrealized gains (losses) relating to instruments still held in the reporting period	50	(113)
Purchases, sales and settlements, net	(24)	84
Transfers in/out, net	(2)	0
Ending Balance, Plan Assets	1,885	1,649
Private Equities
Defined Benefit Plan Disclosure [Line Items]
Beginning Balance, Plan Assets	3,646
Ending Balance, Plan Assets	4,490	3,646
Private Equities | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Beginning Balance, Plan Assets	0	202
Realized gains	0	0
Unrealized gains (losses) relating to instruments still held in the reporting period	0	16
Purchases, sales and settlements, net	0	10
Transfers in/out, net	0	(228)
Ending Balance, Plan Assets	0	0
Corporate Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Beginning Balance, Plan Assets	18,799
Ending Balance, Plan Assets	18,682	18,799
Corporate Bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Beginning Balance, Plan Assets	2	5
Realized gains	0	0
Unrealized gains (losses) relating to instruments still held in the reporting period	0	0
Purchases, sales and settlements, net	0	(3)
Transfers in/out, net	(2)	0
Ending Balance, Plan Assets	0	2
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Beginning Balance, Plan Assets	3,384
Ending Balance, Plan Assets	3,628	3,384
Real Estate [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Beginning Balance, Plan Assets	1,647	1,464
Realized gains	212	7
Unrealized gains (losses) relating to instruments still held in the reporting period	50	(129)
Purchases, sales and settlements, net	(24)	77
Transfers in/out, net	0	228
Ending Balance, Plan Assets	$ 1,885	$ 1,647