Debt And Lines Of Credit Debt and Lines of Credit (Debt Extinguishment Footnotes) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Extinguishment of Debt [Line Items]
Debt instrument, interest rate, stated percentage rate range, minimum		2.00%
Debt instrument, interest rate, stated percentage rate range, maximum		9.375%
Debt Instrument, Maturity Date Range, Start		Jan. 14, 2014
Debt Instrument, Maturity Date Range, End		Sep. 01, 2031
Extinguishment of Debt, Amount	$ 630	$ 2,151	[1]	$ 1,625	[1]	$ 574	[1]
Early Debt Extinguishment Costs [Member]
Extinguishment of Debt [Line Items]
Debt instrument, interest rate, stated percentage rate range, minimum		2.00%		2.00%		2.00%
Debt instrument, interest rate, stated percentage rate range, maximum		9.375%		9.375%		9.375%
Debt Instrument, Maturity Date Range, Start		Jan. 14, 2014		Jan. 14, 2014		Jan. 14, 2014
Debt Instrument, Maturity Date Range, End		Sep. 01, 2031		Sep. 01, 2031		Sep. 01, 2031

[1] Reductions related to notes with interest rates ranging from 2.00% to 9.38% with original maturities from 2014 to 2031 for the years ended December 31, 2015, 2014 and 2013. Includes the $630 million payment for a portion of the Special Purpose Entity Liability (see Note 12 Variable Interest Entities).