v2.4.0.6
Summary of Dividends Declared (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified
9 Months Ended
Sep. 30, 2012
Q1 2012
Sep. 30, 2012
Q2 2012
Sep. 30, 2012
Q3 2012
Sep. 30, 2011
Q1 2011
Sep. 30, 2011
Q2 2011
Sep. 30, 2011
Q3 2011
Dividends Payable [Line Items]            
Declaration Date Feb. 09, 2012 Apr. 25, 2012 Jul. 25, 2012 Feb. 09, 2011 Apr. 27, 2011 Jul. 26, 2011
Dividend Per Share $ 0.09 $ 0.09 $ 0.13 $ 0.14 $ 0.14 $ 0.14
Record Date Mar. 12, 2012 May 30, 2012 Aug. 28, 2012 Mar. 11, 2011 May 27, 2011 Aug. 26, 2011
Total Amount $ 12,204 $ 12,205 $ 18,061 $ 19,352 $ 19,232 $ 19,148
Payment Date Mar. 30, 2012 Jun. 19, 2012 Sep. 18, 2012 Mar. 31, 2011 Jun. 17, 2011 Sep. 16, 2011