Employee Benefit Plans (Severance Accrual) (Details) - Employee Severance [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period	$ 24	$ 23	$ 48
Accruals	170	14	(1)
Benefit payments	(116)	(13)	(24)
Balance at end of period	78	$ 24	$ 23
Short term supplemental unemployment benefits [Member]
Restructuring Cost and Reserve [Line Items]
Balance at end of period	$ 43