v2.4.0.6
SHAREHOLDERS' EQUITY (DETAILS 4) (Common Shares [Member], USD $)
12 Months Ended 3 Months Ended 12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Dec. 31, 2011
Open Market [Member]
Dec. 31, 2010
Open Market [Member]
Dec. 31, 2009
Open Market [Member]
Dec. 31, 2011
From Employees [Member]
Dec. 31, 2010
From Employees [Member]
Dec. 31, 2009
From Employees [Member]
Dec. 31, 2011
Founding Shareholder [Member]
Dec. 31, 2010
Founding Shareholder [Member]
Dec. 31, 2009
Founding Shareholder [Member]
Dec. 31, 2010
Founding Shareholder [Member]
Trident [Member]
Dec. 31, 2011
2007 Plan [Member]
Dec. 31, 2011
2009 Plan [Member]
Dec. 31, 2011
2010 Plan [Member]
Treasury Shares [Line Items]                                
Authorized amounts                           $ 400,000,000 $ 500,000,000 $ 750,000,000
Remaining authorized repurchase amount 544,000,000                              
Number of shares acquired 2,052,000 22,194,000 6,082,000 1,609,000 18,750,000 5,851,000 443,000 381,000 231,000 0 3,063,000 0 3,062,864      
Cost of shares acquired $ 65,885,000 $ 709,583,000 $ 175,909,000 $ 49,974,000 $ 590,694,000 $ 169,620,000 $ 15,911,000 $ 11,062,000 $ 6,289,000 $ 0 $ 107,827,000 $ 0        
Average price of shares acquired $ 32.11 $ 31.97 $ 28.92 $ 31.07 $ 31.50 $ 28.99 $ 35.92 $ 29.04 $ 27.23 $ 0 $ 35.21 $ 0