MERGER AND SELF-MANAGEMENT TRANSACTION - Class M OP Units Conversion (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares
Initial Conversion Ratio
Conversion of Stock [Line Items]
Conversion ratio	0.20
Fiscal Year 2021
Conversion of Stock [Line Items]
AUM conversion threshold | $	$ 860
AFFO conversion threshold (in usd per share) | $ / shares	$ 0.59
Conversion ratio	0.17
Fiscal Year 2022
Conversion of Stock [Line Items]
AUM conversion threshold | $	$ 1,175
AFFO conversion threshold (in usd per share) | $ / shares	$ 0.65
Conversion ratio	0.13
Fiscal Year 2023
Conversion of Stock [Line Items]
AUM conversion threshold | $	$ 1,551
AFFO conversion threshold (in usd per share) | $ / shares	$ 0.70
Conversion ratio	0.11