XML 120 R102.htm IDEA: XBRL DOCUMENT v2.4.0.6
Common Shares (Details Textual) (USD $)
In Millions, except Share data, unless otherwise specified
 12 Months Ended
Dec. 31, 2011
Vote
Dec. 31, 2010
Dec. 31, 2009
Nov. 09, 2011
Nov. 09, 2010
Common Shares (Textual) [Abstract]          
Preference shares included in authorized capital stock 99,760,000        
Shares issued or outstanding 0        
Number of common stock shares to be purchased under the bid       12,000,000 8,000,000
Percentage of issued and outstanding common shares 5.10% 3.30%      
Common shares purchased for cancellation 10,747,300 453,500      
Number of common stock shares repurchased under the bid 3,200,800        
Number of votes per share 1        
Commencement date of bid November 11, 2011 November 11, 2010 November 12, 2008    
Termination date of bid November 10, 2012 November 10, 2011 November 11, 2009    
Cash paid $ 407 $ 23      
Excess of cash paid over the book value $ 162 $ 13