v2.4.0.6
Stockholders' Equity (Details) (USD $)
In Millions, except Share data, unless otherwise specified
3 Months Ended 6 Months Ended
Mar. 31, 2012
Jun. 30, 2011
Mar. 31, 2011
Jun. 30, 2012
Jun. 30, 2011
Dec. 31, 2009
2009 Long Term Incentive Plan [Member]
Jun. 30, 2012
2009 Plan Amendment [Member]
Schedule of Capitalization, Equity [Line Items]              
Plan expiration date       Jun. 02, 2019      
Shares authorized for issuance           21,500,000 47,000,000
Calculated shares issued subsequent to plan amendment, other awards       2.38      
Dividends paid on common stock       $ 162 $ 140    
Dividends paid on common stock, per share $ 0.20 $ 0.17 $ 0.16