XML 66 R49.htm IDEA: XBRL DOCUMENT v2.4.0.6
Selected Quarterly Financial Data (Unaudited) (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
 3 Months Ended 12 Months Ended
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2011
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Selected Quarterly Financial Data (Unaudited)                      
Revenues $ 322,311 $ 330,068 $ 343,183 $ 301,420 $ 295,851 $ 318,689 $ 313,809 $ 281,984 $ 1,296,982 $ 1,210,333 $ 1,085,488
Net income 26,631 44,658 37,686 42,948 38,218 47,531 51,643 53,048 151,923 190,440 21,351
Net income available for common shareholders $ 18,534 $ 29,480 $ 26,964 $ 28,816 $ 30,748 $ 40,061 $ 44,173 $ 45,578 $ 103,794 $ 160,560 $ (8,529)
Net income available for common shareholders per share (in dollars per share) $ 0.15 $ 0.24 $ 0.22 $ 0.23 $ 0.25 $ 0.32 $ 0.36 $ 0.37 $ 0.84 $ 1.30 $ (0.07)
Distribution to common shareholders (in dollars per share) $ 0.47 $ 0.45 $ 0.45 $ 0.45 $ 0.45 $ 0.45 $ 0.45 $ 0.45      
Period considered for computing sum of per common share amount                 1 year