Income Tax (Total Income Taxes Provided) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Effects Allocated Directly to Equity [Abstract]
Provision for income taxes	$ 74	$ 138	$ 262
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	(520)	611	681
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	23	(9)	3
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax	7	(1)	(5)
Income Tax Expense (Benefit), Intraperiod Tax Allocation	$ (416)	$ 739	$ 941