(Debt Extinguishment) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Extinguishment of Debt [Line Items]
Early debt reductions (a)	[1]	$ 1,640	$ 614	$ 780
Pre-tax early debt extinguishment costs (b)	[2]	$ 196	$ 21	$ 10

[1] Reductions related to notes with interest rates ranging from 3.00% to 9.50% with original maturities from 2021 to 2048 for the years ended December 31, 2020, 2019 and 2018.

[2] Amounts are included in Restructuring and other charges in the accompanying consolidated statements of operations.