Quarterly Financial Data (Schedule Of Quarterly Financial Data) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Quarterly Financial Data [Abstract]
Total revenues	$ 19,555	$ 17,727	$ 16,543	$ 14,910	$ 16,550	$ 16,967	$ 15,573	$ 15,216	$ 68,735	$ 64,306	$ 68,281
Total costs and expenses	(16,261)	(14,357)	(13,200)	(12,049)	(13,413)	(13,746)	(12,540)	(12,144)	(55,867)	(51,843)	(56,540)
Earnings from operations	1,597	1,714	1,534	1,000	1,103	1,387	1,307	1,174	5,844	4,971	2,096
Net earnings from continuing operations	1,387	1,094	942	588	1,166	837	789	519	4,011	3,311	1,335
Net gain/(loss) from discontinued operations	6	4	(1)	(2)	(2)		(2)		7	(4)	(23)
Net earnings	$ 1,393	$ 1,098	$ 941	$ 586	$ 1,164	$ 837	$ 787	$ 519	$ 4,018	$ 3,307	$ 1,312
Basic earnings per share from continuing operations	$ 1.85	$ 1.47	$ 1.27	$ 0.79	$ 1.57	$ 1.13	$ 1.07	$ 0.71	$ 5.38	$ 4.50	$ 1.89
Basic earnings per share	$ 1.86	$ 1.47	$ 1.27	$ 0.79	$ 1.57	$ 1.13	$ 1.07	$ 0.71	$ 5.39	$ 4.49	$ 1.86
Diluted earnings per share from continuing operations	$ 1.83	$ 1.46	$ 1.25	$ 0.78	$ 1.56	$ 1.12	$ 1.06	$ 0.70	$ 5.33	$ 4.46	$ 1.87
Diluted earnings per share	$ 1.84	$ 1.46	$ 1.25	$ 0.78	$ 1.56	$ 1.12	$ 1.06	$ 0.70	$ 5.34	$ 4.45	$ 1.84
Cash dividends declared per share	$ 0.86		$ 0.84		$ 0.84		$ 0.84		$ 1.7	$ 1.68	$ 1.68
High	$ 74.74	$ 76.20	$ 80.65	$ 74.47	$ 72.49	$ 70.00	$ 76.00	$ 74.53
Low	$ 56.90	$ 56.01	$ 70.29	$ 66.00	$ 61.84	$ 59.48	$ 59.84	$ 54.80
Quarter end	$ 73.35	$ 60.51	$ 73.93	$ 73.93	$ 65.26	$ 66.54	$ 62.75	$ 72.61