Notes Receivable, Net - Schedule of Notes Receivable (Parenthetical) (Details) $ in Thousands	Mar. 31, 2020 USD ($) NotesReceivable	Dec. 31, 2019 USD ($)	Mar. 28, 2018	Nov. 16, 2017
Accounts Notes And Loans Receivable [Line Items]
Number of notes receivable | NotesReceivable	9
Notes receivable	$ 174,089	$ 114,943
Core Portfolio
Accounts Notes And Loans Receivable [Line Items]
Number of notes receivable | NotesReceivable	7
Notes receivable	$ 135,467	76,467
Equity method investment, ownership percentage by third party	24.78%		14.11%	38.89%
Core Portfolio | Brandywine Portfolio
Accounts Notes And Loans Receivable [Line Items]
Notes receivable	$ 38,700
OP Unit Holders | Core Portfolio
Accounts Notes And Loans Receivable [Line Items]
Number of notes receivable | NotesReceivable	2
Notes receivable	$ 6,500	$ 6,500