Debt And Credit Facilities (Long-Term Debt) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Other long-term debt	$ 50	$ 53
Long-term debt, Gross	1,492	2,633
Adjustments, primarily unamortized gains on interest rate swap terminations	43	70
Less: current portion	(405)	(605)
Long-term debt	1,130	2,098
8.0% Notes Due 2011 [Member]
Debt Instrument [Line Items]
Long-term debt, Gross	0	600
Long-term debt, interest rate	8.00%
Long-term debt, maturity year	2011
5.375% Senior Notes Due 2012 [Member]
Debt Instrument [Line Items]
Long-term debt, Gross	400	400
Long-term debt, interest rate	5.375%
Long-term debt, maturity year	2012
6.0% Senior Notes Due 2017 [Member]
Debt Instrument [Line Items]
Long-term debt, Gross	399	399
Long-term debt, interest rate	6.00%
Long-term debt, maturity year	2017
6.5% Debentures Due 2025 [Member]
Debt Instrument [Line Items]
Long-term debt, Gross	118	313
Long-term debt, interest rate	6.50%
Long-term debt, maturity year	2025
7.5% Debentures Due 2025 [Member]
Debt Instrument [Line Items]
Long-term debt, Gross	346	346
Long-term debt, interest rate	7.50%
Long-term debt, maturity year	2025
6.5% Debentures Due 2028 [Member]
Debt Instrument [Line Items]
Long-term debt, Gross	36	209
Long-term debt, interest rate	6.50%
Long-term debt, maturity year	2028
6.625% Senior Notes Due 2037 [Member]
Debt Instrument [Line Items]
Long-term debt, Gross	54	224
Long-term debt, interest rate	6.625%
Long-term debt, maturity year	2037
5.22% Debentures Due 2097 [Member]
Debt Instrument [Line Items]
Long-term debt, Gross	$ 89	$ 89
Long-term debt, interest rate	5.22%
Long-term debt, maturity year	2097