FAIR VALUE MEASUREMENTS (Details 2) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Long-term Debt, Fair Value	$ 4,078.7	$ 3,570.5	$ 3,552.6
Notes Payable	3,960.7	3,340.8	3,340.1
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	3,925.7	3,417.5	3,399.6
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