FAIR VALUE MEASUREMENTS (Details 2) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Long-term Debt, Fair Value	$ 3,415.6	$ 3,290.2	$ 3,674.6
Notes Payable	3,233.7	3,230.3	3,513.5
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	3,262.6	3,137.2	3,521.6
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