Notes Receivable, net and Other - Narrative (Details)	3 Months Ended
	Mar. 31, 2021 USD ($) a	Mar. 31, 2020 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cash interest income	$ 0	$ 0
Discount amortization	145,000	135,000
Interest income	13,000	611,000
Future ownership rights of parking parcel
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income	78,000	73,000
Free use of parking easement prior to development commencement
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortization expense		117,000
Accumulated amortization	0	0
Reimbursement of parking fees while parking parcel is in development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income	4,000	0
Reimbursement of parking fees	$ 120,000	$ 120,000
Parking Lot Adjacent to Hilton St. Petersburg Bayfront Hotel | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Area of property (in acres) | a	1.65