Consolidated Statements of Operations (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Consolidated Statements of Operations [Abstract]
Revenues	$ 4,040,000,000	$ 3,796,000,000
Expenses:
Operating	2,474,000,000	2,347,000,000
Selling, general and administrative	650,000,000	642,000,000
Impairment charges (Note 3)	0	11,000,000
Depreciation and amortization	116,000,000	119,000,000
Total expenses	3,240,000,000	3,119,000,000
Operating income (loss)	800,000,000	677,000,000
Interest expense	(95,000,000)	(110,000,000)
Interest income	2,000,000	2,000,000
Gain on early extinguishment of debt (Note 7)	0	25,000,000
Other items, net	(2,000,000)	5,000,000
Earnings (loss) from continuing operations before income taxes and equity in earnings (loss) of investee companies	705,000,000	599,000,000
(Provision) benefit for income taxes	(234,000,000)	(201,000,000)
Equity in loss of investee companies, net of tax	(8,000,000)	(4,000,000)
Net earnings (loss) from continuing operations	463,000,000	394,000,000
Net loss from discontinued operations, net of tax	(20,000,000)	(31,000,000)
Net earnings	$ 443,000,000	$ 363,000,000
Basic net earnings (loss) per common share:
Basic net earnings (loss) from continuing operations (in dollars per share)	$ 0.75	$ 0.61
Basic net earnings (loss) from discontinued operations (in dollars per share)	$ (0.03)	$ (0.05)
Basic net earnings (loss) per common share (in dollars per share)	$ 0.71	$ 0.56
Diluted net earnings (loss) per common share:
Diluted net earnings (loss) from continuing operations (in dollars per share)	$ 0.73	$ 0.59
Diluted net earnings (loss) from discontinued operations (in dollars per share)	$ (0.03)	$ (0.05)
Diluted net earnings per common share (in dollars per share)	$ 0.69	$ 0.54
Weighted average number of common shares outstanding:
Basic weighted average number of common shares outstanding	621	650
Diluted weighted average number of common shares outstanding	638	667
Dividends per common share (in dollars per share)	$ 0.12	$ 0.10