Organization, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Operating Partnership's Equity Interest (Details) - USD ($) $ in Millions	1 Months Ended			12 Months Ended
	Aug. 31, 2020	Jun. 30, 2020	Apr. 30, 2018	Dec. 31, 2020
Mervyns II
Variable Interest Entity [Line Items]
Recallable distributions	$ 15.7
Mervyns II | Acadia
Variable Interest Entity [Line Items]
Recallable distributions	$ 4.5
Operating Partnership, as General Partner or Managing Member
Variable Interest Entity [Line Items]
Total Distributions			$ 4.3
Fund II and Mervyns II
Variable Interest Entity [Line Items]
Operating Partnership Share of Capital				28.33%
Capital Called				$ 369.6
Unfunded Commitment				$ 15.7
Equity interest held by Operating Partnership				28.33%
Preferred Return				8.00%
Total Distributions				$ 169.8
Fund III
Variable Interest Entity [Line Items]
Operating Partnership Share of Capital				24.54%
Capital Called				$ 448.1
Unfunded Commitment				$ 1.9
Equity interest held by Operating Partnership				24.54%
Preferred Return				6.00%
Total Distributions				$ 568.8
Fund IV
Variable Interest Entity [Line Items]
Operating Partnership Share of Capital				23.12%
Capital Called				$ 469.5
Unfunded Commitment				$ 60.5
Equity interest held by Operating Partnership				23.12%
Preferred Return				6.00%
Total Distributions				$ 193.1
Fund V
Variable Interest Entity [Line Items]
Operating Partnership Share of Capital				20.10%
Capital Called				$ 217.1
Unfunded Commitment				$ 302.9
Equity interest held by Operating Partnership				20.10%
Preferred Return				6.00%
Total Distributions				$ 24.6
Fund II
Variable Interest Entity [Line Items]
Total Distributions			$ 15.0
Fund II | Mervyns II
Variable Interest Entity [Line Items]
Total Distributions		$ 7.5