v2.4.0.8
Selected Quarterly Data Summary of Selected Quarterly Data (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2013
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2011
Sep. 30, 2013
Sep. 30, 2012
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Quarterly Financial Information Disclosure [Abstract]                            
Revenue $ 1,298,094 $ 1,067,915 [1] $ 1,016,707 [1] $ 1,006,531 [1] $ 1,031,777 [1] $ 939,632 $ 783,898 $ 759,684 $ 786,648 $ 3,745,839 $ 3,055,015 $ 4,122,930 $ 3,269,862 $ 2,469,881
Gross margin 517,907 445,121 [1] 409,705 [1] 421,931 [1] 447,383 [1] 391,789 334,322 322,236 343,646 1,529,729 1,279,019 1,724,140 1,391,993 1,093,480
Operating income 123,395 104,344 [1] 91,434 [1] 108,567 [1] 133,608 [1] 90,138 85,488 78,486 107,371 396,361 333,609 437,953 361,483 297,877
Net income $ 73,445 $ 62,188 [1] $ 54,048 [1] $ 63,998 [1] $ 80,991 [1] $ 56,145 $ 49,231 $ 46,706 $ 58,182 $ 233,759 $ 199,037 $ 261,225 $ 210,264 $ 169,071
Earnings Per Share, Basic $ 0.24 $ 0.21 [1] $ 0.18 [1] $ 0.22 [1] $ 0.28 [1] $ 0.19 [1] $ 0.17 [1] $ 0.16 [1] $ 0.20 [1] $ 0.78 $ 0.67 $ 0.88 [2] $ 0.72 [2] $ 0.59 [2]
Earnings Per Share, Diluted $ 0.24 $ 0.21 [1] $ 0.18 [1] $ 0.21 [1] $ 0.27 [1] $ 0.19 [1] $ 0.17 [1] $ 0.16 [1] $ 0.20 [1] $ 0.77 $ 0.66 $ 0.87 [2] $ 0.71 [2] $ 0.58 [2]
[1] Gross margin and operating income during the quarters ended March 31, 2012, June 30, 2012, September 30, 2012 and December 31, 2012 include gains of $8.3 million, $8.4 million, $0.5 million and $0.7 million, respectively, resulting from lawsuit settlements with certain of our aftermarket product suppliers as discussed in Note 8, "Commitments and Contingencies."
[2] The sum of the individual earnings per share amounts may not equal the total due to rounding.