Condensed Consolidating Financial Data (Condensed Consolidating Balance Sheets) (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Current assets	$ 3,521.6	$ 3,370.8
Non-current assets	3,715.2	3,722.2
Total assets	7,236.8	7,093.0
Current liabilities	1,495.1	1,677.2
Non-current liabilities	3,806.6	3,595.3
Stockholders' equity	1,935.1	1,820.5
Total liabilities and stockholders' equity	7,236.8	7,093.0
Parent [Member]
Current assets	169.0	314.6
Investment in subsidiaries	5,678.5	5,340.3
Non-current assets	149.4	153.7
Total assets	5,996.9	5,808.6
Current liabilities	249.8	217.4
Non-current liabilities	3,812.0	3,770.7
Stockholders' equity	1,935.1	1,820.5
Total liabilities and stockholders' equity	5,996.9	5,808.6
Guarantor Subsidiaries [Member]
Current assets	1,198.6	998.6
Investment in subsidiaries	1,622.4	1,739.8
Non-current assets	3,968.0	3,768.8
Total assets	6,789.0	6,507.2
Current liabilities	652.5	588.5
Non-current liabilities	479.9	504.3
Stockholders' equity	5,656.6	5,414.4
Total liabilities and stockholders' equity	6,789.0	6,507.2
Non-Guarantor Subsidiaries [Member]
Current assets	2,164.0	2,067.6
Investment in subsidiaries	0.3	93.4
Non-current assets	964.0	1,015.1
Total assets	3,128.3	3,176.1
Current liabilities	599.4	878.0
Non-current liabilities	884.3	539.0
Stockholders' equity	1,644.6	1,759.1
Total liabilities and stockholders' equity	3,128.3	3,176.1
Eliminations [Member]
Current assets	(10.0)	(10.0)
Investment in subsidiaries	(7,301.2)	(7,173.5)
Non-current assets	(1,366.2)	(1,215.4)
Total assets	(8,677.4)	(8,398.9)
Current liabilities	(6.6)	(6.7)
Non-current liabilities	(1,369.6)	(1,218.7)
Stockholders' equity	(7,301.2)	(7,173.5)
Total liabilities and stockholders' equity	$ (8,677.4)	$ (8,398.9)