Quarterly Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 1,694,600	$ 1,787,582	$ 1,758,628	$ 1,715,501	$ 1,977,947	$ 2,009,575	$ 1,962,636	$ 1,802,570	$ 6,956,311	$ 7,752,728	$ 7,155,096
Gross profit	613,809	672,608	654,568	627,159	723,868	774,422	768,100	707,859	2,568,144	2,974,249	2,778,591
Earnings from continuing operations	$ 136,574	$ 186,483	$ 155,634	$ 117,190	$ 171,835	$ 225,683	$ 210,581	$ 170,041	$ 595,881	$ 778,140	$ 797,527
Earnings from continuing operations (in dollars per basic share)	$ 0.88	$ 1.20	$ 0.98	$ 0.72	$ 1.04	$ 1.36	$ 1.26	$ 1.00	$ 3.78	$ 4.67	$ 4.66
Earnings from continuing operations (in dollars per diluted share)	$ 0.87	$ 1.19	$ 0.97	$ 0.72	$ 1.03	$ 1.34	$ 1.25	$ 0.99	$ 3.74	$ 4.61	$ 4.60
Net earnings	$ 141,825	$ 186,098	$ 332,396	$ 209,510	$ 169,294	$ 231,844	$ 213,959	$ 160,138	$ 869,829	$ 775,235	$ 1,003,129
Net earnings (in dollars per basic share)	$ 0.92	$ 1.20	$ 2.10	$ 1.30	$ 1.03	$ 1.40	$ 1.29	$ 0.94	$ 5.52	$ 4.65	$ 5.86
Net earnings (in dollars per diluted share)	$ 0.91	$ 1.19	$ 2.07	$ 1.28	$ 1.02	$ 1.38	$ 1.27	$ 0.93	$ 5.46	$ 4.59	$ 5.78