Fair Value of Other Instruments (Details) (USD $)
In Millions, unless otherwise specified |
Dec. 31, 2012
|
Dec. 31, 2011
|
---|---|---|
Other Financial Instruments [Abstract] | ||
Notes Receivable - Carrying Value | $ 4.7 | $ 6.5 |
Notes Receivable - Fair Value | 4.7 | 6.5 |
Carrying Value and Fair Value of Other Financial Instruments [Line Items] | ||
Debt Obligations - Carrying Value | 7,124.3 | 7,028.0 |
Debt Obligations - Fair Value | 7,560.0 | 7,389.6 |
Senior Notes [Member]
|
||
Carrying Value and Fair Value of Other Financial Instruments [Line Items] | ||
Debt Obligations - Carrying Value | 7,019.5 | 6,093.0 |
Debt Obligations - Fair Value | 7,455.2 | 6,454.6 |
U.S. Commercial Paper Program [Member]
|
||
Carrying Value and Fair Value of Other Financial Instruments [Line Items] | ||
Debt Obligations - Carrying Value | 50.0 | 900.0 |
Debt Obligations - Fair Value | 50.0 | 900.0 |
Other Debt [Member]
|
||
Carrying Value and Fair Value of Other Financial Instruments [Line Items] | ||
Debt Obligations - Carrying Value | 54.8 | 35.0 |
Debt Obligations - Fair Value | $ 54.8 | $ 35.0 |