Contingencies and Commitments (Finance Lease Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Contingencies and Commitments [Abstract]
Amortization of ROU assets	$ 38	$ 53	$ 67
Interest on lease liabilities	3	6	13
Total	$ 41	$ 59	$ 80