FAIR VALUE MEASUREMENTS (Details 2) - USD ($) $ in Millions |
Sep. 30, 2017 |
Dec. 31, 2016 |
Sep. 30, 2016 |
|---|---|---|---|
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | |||
| Long-term Debt, Fair Value | $ 4,073.5 | $ 3,856.7 | $ 3,885.7 |
| Notes Payable | 3,745.2 | 3,617.6 | 3,677.8 |
| Fair Value, Inputs, Level 1 | |||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | |||
| Long-term Debt, Fair Value | 0.0 | 0.0 | 0.0 |
| Fair Value, Inputs, Level 2 | |||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | |||
| Long-term Debt, Fair Value | 3,920.5 | 3,703.7 | 3,732.7 |
| Fair Value, Inputs, Level 3 | |||
| Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] | |||
| Long-term Debt, Fair Value | $ 153.0 | $ 153.0 | $ 153.0 |