XML 28 R57.htm IDEA: XBRL DOCUMENT v2.4.0.6
Debt (Details 2) (USD $)
 12 Months Ended 0 Months Ended 0 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2012
Fixed rate senior notes
Dec. 31, 2011
Fixed rate senior notes
Dec. 31, 2012
2.85% senior notes due January 2023
Dec. 31, 2012
4.30% senior notes due January 2043
Dec. 31, 2012
3.65% senior notes due June 2022
Mar. 31, 2012
3.65% senior notes due June 2022
Dec. 31, 2012
5.15% senior notes due June 2042
Mar. 31, 2012
5.15% senior notes due June 2042
Dec. 31, 2012
5.00% senior notes due February 2021
Dec. 31, 2011
5.00% senior notes due February 2021
Jan. 31, 2011
5.00% senior notes due February 2021
Dec. 31, 2012
3.95% senior notes due September 2015
Dec. 31, 2011
3.95% senior notes due September 2015
Jul. 31, 2010
3.95% senior notes due September 2015
Sep. 04, 2012
4.25% senior notes due September 2012
Dec. 31, 2011
4.25% senior notes due September 2012
Feb. 07, 2011
7.75% senior notes due October 2012
Sep. 15, 2010
6.25% senior notes due September 2015
Debt                                          
Debt instrument face value       $ 6,300,000,000 $ 4,800,000,000 $ 400,000,000 $ 350,000,000   $ 750,000,000   $ 500,000,000     $ 600,000,000     $ 400,000,000     $ 200,000,000 $ 175,000,000
Debt instrument fair value       7,300,000,000 5,400,000,000                                
Debt instrument face value 500,000,000 200,000,000 175,000,000                             500,000,000      
Debt instrument, interest rate (as a percent)           2.85% 4.30% 3.65% 3.65% 5.15% 5.15% 5.00% 5.00% 5.00% 3.95% 3.95% 3.95% 4.25% 4.25% 7.75% 6.25%
Percentage of face value at which senior notes are sold           99.752% 99.925%   99.823%   99.755%     99.521%     99.889%        
Consolidated subsidiary, ownership interest held by the parent (as a percent) 100.00%                                        
Loss on early redemption of senior notes                                       $ (23,000,000) $ (6,000,000)