Annual report pursuant to Section 13 and 15(d)

Dividends (Details)

v2.4.0.6
Dividends (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2011
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Summary of Dividends paid        
Declaration Date   Nov. 02, 2010    
Dividends declared per common share $ 0.21 $ 0.21    
Total dividend paid   $ 96,522 $ 85,137 $ 78,844
First quarter dividend [Member]
       
Summary of Dividends paid        
Declaration Date   Feb. 24, 2011 Feb. 25, 2010 Feb. 13, 2009
Record Date   Mar. 04, 2011 Mar. 05, 2010 Mar. 05, 2009
Date Paid   Mar. 16, 2011 Mar. 19, 2010 Mar. 20, 2009
Dividends declared per common share   $ 0.21 $ 0.18 $ 0.18
Total dividend paid   24,056 20,104 19,619
Second quarter dividend [Member]
       
Summary of Dividends paid        
Declaration Date   May 12, 2011 May 13, 2010 May 13, 2009
Record Date   Jun. 06, 2011 Jun. 04, 2010 Jun. 02, 2009
Date Paid   Jun. 17, 2011 Jun. 18, 2010 Jun. 18, 2009
Dividends declared per common share   $ 0.21 $ 0.18 $ 0.18
Total dividend paid   24,152 20,313 19,734
Third quarter dividend [Member]
       
Summary of Dividends paid        
Declaration Date   Aug. 03, 2011 Jul. 29, 2010 Jul. 29, 2009
Record Date   Aug. 17, 2011 Aug. 17, 2010 Aug. 17, 2009
Date Paid   Sep. 01, 2011 Sep. 01, 2010 Sep. 01, 2009
Dividends declared per common share   $ 0.21 $ 0.18 $ 0.18
Total dividend paid   24,157 20,519 19,739
Fourth Quarter Dividend [Member]
       
Summary of Dividends paid        
Declaration Date   Nov. 03, 2011 Nov. 02, 2010 Nov. 04, 2009
Record Date   Nov. 18, 2011 Nov. 22, 2010 Nov. 25, 2009
Date Paid   Dec. 07, 2011 Dec. 07, 2010 Dec. 10, 2009
Dividends declared per common share   $ 0.21 $ 0.21 $ 0.18
Total dividend paid   24,157 24,201 19,752
Restricted Stock Units R S U [Member]
       
Summary of Dividends paid        
Dividends related to outstanding restricted stock units   $ 684 $ 635 $ 201