Debt And Lines Of Credit (Debt Extinguishment) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Extinguishment of Debt [Line Items]
Debt reductions (a)	[1]	$ 993	$ 266	$ 2,151
Pre-tax early debt extinguishment costs (b)	[2]	$ 83	$ 29	$ 207

[1] Reductions related to notes with interest rates ranging from 1.57% to 9.38% with original maturities from 2015 to 2030 for the years ended December 31, 2017, 2016 and 2015. Includes the $630 million payment for a portion of the Special Purpose Entity Liability for the year ended December 31, 2015 (see Note 12 Variable Interest Entities).

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