OTHER ASSETS - Schedule of Other Assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Other Assets [Abstract]
Loan purchases and originations	$ 107.1	$ 37.5
Straight line rent receivable	51.6	47.3
Deferred taxes, net	22.1	24.4
Goodwill	23.9	23.9
Other, net of accumulated amortization of $2.1 and $2.0 at December 31, 2020 and 2019, respectively	19.0	16.5
Hedge Asset	12.0	32.6
Prepaid expenses	11.8	14.3
Right of use asset, net	11.2	13.6
Leasing commissions, net of accumulated amortization of $7.4 and $4.7 at December 31, 2020 and 2019, respectively	10.2	11.9
Other Assets	306.2	271.8
Accumulated depreciation, depletion and amortization, property, plant, and equipment	27.2	21.9
Accumulated amortization, other	2.1	2.0
Accumulated amortization, above-market leases	58.3	51.0
Accumulated amortization, leasing commission	7.4	4.7
Furniture and equipment
Other Assets [Abstract]
Furniture and equipment net of accumulated depreciation of $27.2 and $21.9 at December 31, 2020 and December 31, 2019, respectively	22.3	23.7
Above market Leases
Other Assets [Abstract]
Above-market leases, net of accumulated amortization of $58.3 and $51.0 at December 31, 2020 and 2019, respectively	$ 15.0	$ 26.1