Consolidated Statements of Operations (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Consolidated Statements of Operations [Abstract]
Revenues	$ 3,699,000,000	$ 3,329,000,000	$ 7,739,000,000	$ 7,125,000,000
Expenses:
Operating	2,064,000,000	1,753,000,000	4,538,000,000	4,100,000,000
Selling, general and administrative	683,000,000	665,000,000	1,333,000,000	1,307,000,000
Impairment charges (Note 3)	0	0	0	11,000,000
Depreciation and amortization	114,000,000	119,000,000	230,000,000	238,000,000
Total expenses	2,861,000,000	2,537,000,000	6,101,000,000	5,656,000,000
Operating income (loss)	838,000,000	792,000,000	1,638,000,000	1,469,000,000
Interest expense	(93,000,000)	(104,000,000)	(188,000,000)	(214,000,000)
Interest income	2,000,000	1,000,000	4,000,000	3,000,000
Gain on early extinguishment of debt	0	0	0	25,000,000
Other items, net	(7,000,000)	3,000,000	(9,000,000)	8,000,000
Earnings (loss) from continuing operations before income taxes and equity in earnings (loss) of investee companies	740,000,000	692,000,000	1,445,000,000	1,291,000,000
(Provision) benefit for income taxes	(256,000,000)	(228,000,000)	(490,000,000)	(429,000,000)
Equity in loss of investee companies, net of tax	(8,000,000)	(12,000,000)	(16,000,000)	(16,000,000)
Net earnings (loss) from continuing operations	476,000,000	452,000,000	939,000,000	846,000,000
Net loss from discontinued operations, net of tax (Note 4)	(4,000,000)	(25,000,000)	(24,000,000)	(56,000,000)
Net earnings	$ 472,000,000	$ 427,000,000	$ 915,000,000	$ 790,000,000
Basic net earnings (loss) per common share:
Basic net earnings (loss) from continuing operations (in dollars per share)	$ 0.78	$ 0.70	$ 1.53	$ 1.31
Basic net earnings (loss) from discontinued operations (in dollars per share)	$ (0.01)	$ (0.04)	$ (0.04)	$ (0.09)
Basic net earnings (loss) per common share (in dollars per share)	$ 0.78	$ 0.66	$ 1.49	$ 1.22
Diluted net earnings (loss) per common share:
Diluted net earnings (loss) from continuing operations (in dollars per share)	$ 0.76	$ 0.68	$ 1.49	$ 1.27
Diluted net earnings (loss) from discontinued operations (in dollars per share)	$ (0.01)	$ (0.04)	$ (0.04)	$ (0.08)
Diluted net earnings per common share (in dollars per share)	$ 0.76	$ 0.65	$ 1.45	$ 1.19
Weighted average number of common shares outstanding:
Basic weighted average number of common shares outstanding	609	646	615	648
Diluted weighted average number of common shares outstanding	624	661	631	664
Dividends per common share (in dollars per share)	$ 0.12	$ 0.10	$ 0.24	$ 0.20