Condensed Consolidated Statements of Income (Unaudited) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues
Sales	$ 1,803.0	$ 1,612.0
Other revenues	235.6	131.1
Total revenues	2,038.6	1,743.1
Costs and expenses
Operating costs and expenses	1,438.6	1,247.2
Depreciation, depletion and amortization	(144.9)	(107.7)
Asset retirement obligation expense	15.2	13.3
Selling and administrative expenses	71.0	61.6
Other operating (income) loss:
Net gain on disposal or exchange of assets	(4.0)	(4.0)
Loss (income) from equity affiliates	22.7	3.0
Operating profit	350.2	314.3
Interest expense	102.0	51.0
Interest income	(8.1)	(4.1)
Income from continuing operations before income taxes	256.3	267.4
Income tax provision	74.0	72.8
Income from continuing operations, net of income taxes	182.3	194.6
Loss from discontinued operations, net of income taxes	(4.0)	(15.9)
Net income	178.3	178.7
Less: Net income attributable to noncontrolling interests	5.6	2.2
Net income attributable to common stockholders	172.7	176.5
Income From Continuing Operations
Basic earnings per share	$ 0.64	$ 0.71
Diluted earnings per share	$ 0.64	$ 0.70
Net Income Attributable to Common Stockholders
Basic earnings per share	$ 0.63	$ 0.66
Diluted earnings per share	$ 0.63	$ 0.65
Dividends declared per share	$ 0.085	$ 0.085
Retained Earnings [Member]
Other operating (income) loss:
Net income	$ 172.7