v2.4.0.6
Segment Reporting (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2011
Dec. 31, 2010
Sep. 30, 2010
Jun. 30, 2010
Mar. 31, 2010
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Summarized financial information concerning our reportable segments                      
Gross Revenue                 $ 9,742.8 $ 9,686.0 $ 9,819.0
Intercompany Revenue                 (1,549.9) (1,579.4) (1,619.9)
Net Revenue 2,025.2 2,116.2 2,086.6 1,964.9 2,020.8 2,061.7 2,066.4 1,957.7 8,192.9 8,106.6 8,199.1
Depreciation, amortization and depletion                 843.6 833.7 869.7
Operating (loss) income 366.7 408.5 401.2 376.2 389.4 367.6 400.8 381.3 1,552.7 1,539.1 1,589.8
Capital Expenditures                 936.5 794.7 826.3
Total Assets 19,551.5       19,461.9       19,551.5 19,461.9 19,540.3
Reportable Segments [Member]
                     
Summarized financial information concerning our reportable segments                      
Depreciation, amortization and depletion                 921.6 914.2 958.5
Eastern [Member]
                     
Summarized financial information concerning our reportable segments                      
Gross Revenue                 2,469.2 2,429.3 2,485.9
Intercompany Revenue                 (366.1) (353.8) (370.9)
Net Revenue                 2,103.1 2,075.5 2,115.0
Depreciation, amortization and depletion                 202.4 205.5 214.3
Operating (loss) income                 493.0 488.4 483.0
Capital Expenditures                 219.9 175.3 199.1
Total Assets 4,457.0       4,437.1       4,457.0 4,437.1 4,495.1
Midwestern [Member]
                     
Summarized financial information concerning our reportable segments                      
Gross Revenue                 2,197.4 2,167.4 2,185.4
Intercompany Revenue                 (390.9) (400.5) (408.4)
Net Revenue                 1,806.5 1,766.9 1,777.0
Depreciation, amortization and depletion                 206.5 203.6 225.9
Operating (loss) income                 375.9 402.0 367.3
Capital Expenditures                 218.0 210.7 208.7
Total Assets 3,794.4       3,718.0       3,794.4 3,718.0 3,605.9
Southern [Member]
                     
Summarized financial information concerning our reportable segments                      
Gross Revenue                 2,343.0 2,289.0 2,371.7
Intercompany Revenue                 (313.1) (311.7) (325.5)
Net Revenue                 2,029.9 1,977.3 2,046.2
Depreciation, amortization and depletion                 229.9 221.5 233.1
Operating (loss) income                 460.7 482.8 522.9
Capital Expenditures                 229.3 190.4 168.5
Total Assets 4,907.7       4,869.7       4,907.7 4,869.7 4,867.6
Western [Member]
                     
Summarized financial information concerning our reportable segments                      
Gross Revenue                 2,619.2 2,684.6 2,652.4
Intercompany Revenue                 (463.5) (496.0) (482.4)
Net Revenue                 2,155.7 2,188.6 2,170.0
Depreciation, amortization and depletion                 220.5 218.2 234.9
Operating (loss) income                 486.4 521.2 582.0
Capital Expenditures                 267.4 222.3 180.5
Total Assets 5,539.0       5,518.5       5,539.0 5,518.5 5,461.2
Corporate entities [Member]
                     
Summarized financial information concerning our reportable segments                      
Gross Revenue                 114.0 115.7 123.6
Intercompany Revenue                 (16.3) (17.4) (32.7)
Net Revenue                 97.7 98.3 90.9
Depreciation, amortization and depletion                 62.3 65.4 50.3
Operating (loss) income                 (263.3) (355.3) (365.4)
Capital Expenditures                 1.9 (4.0) 69.5
Total Assets $ 853.4       $ 918.6       $ 853.4 $ 918.6 $ 1,110.5