Annual report pursuant to Section 13 and 15(d)

Quarterly Financial Information (Summary Of Quarterly Financial Information) (Details)

v2.4.0.6
Quarterly Financial Information (Summary Of Quarterly Financial Information) (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 Information [Abstract]                      
Revenue $ 527,345 $ 544,493 $ 541,505 $ 497,140 $ 485,132 $ 494,475 $ 480,255 $ 422,679 $ 2,110,483 $ 1,882,541 $ 1,480,998
Operating income 67,516 80,932 82,588 54,218 63,312 68,194 64,645 37,921 285,254 234,072 137,739
Net income $ 39,481 $ 51,044 $ 47,832 $ 31,095 $ 39,883 $ 38,631 $ 39,383 $ 21,573 $ 169,452 $ 139,470 $ 75,651
Basic and diluted $ 0.46 $ 0.59 $ 0.56 $ 0.36 $ 0.46 $ 0.45 $ 0.46 $ 0.26 $ 1.97 $ 1.63