Business Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Business Segments [Abstract]
Number of reportable segments	5
Segment Gross Operating Margin [Abstract]
Revenues	$ 11,383.1	$ 11,252.5
Less: Operating costs and expenses	(10,420.4)	(10,467.2)
Add: Equity in income of unconsolidated affiliates	44.5	9.9
Depreciation, amortization and accretion recorded in operating costs and expenses	276.8	254.6
Non-cash asset impairment charges recorded in operating costs and expenses	11.0	5.4
Gains attributable to asset sales and insurance recoveries recorded in operating costs and expenses	(63.9)	(2.5)
Total segment gross operating margin	1,231.1	1,052.7
Reconciliation of total Segment Gross Operating Margin [Abstract]
Total segment gross operating margin	1,231.1	1,052.7
Adjustments to reconcile total segment gross operating margin to operating income:
Depreciation, amortization and accretion	(276.8)	(254.6)
Non-cash asset impairment charges	(11.0)	(5.4)
Gains attributable to asset sales and insurance recoveries	63.9	2.5
General and administrative costs	(49.5)	(46.3)
Operating income	957.7	748.9
Other expense, net	(196.0)	(127.8)
Income before income taxes	$ 761.7	$ 621.1