Commitments and Contingencies - Additional Information (Detail) ft² in Thousands	1 Months Ended		3 Months Ended		12 Months Ended
	Mar. 31, 2016 USD ($)	Feb. 28, 2014 fire	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2021 USD ($)	Apr. 13, 2019 ft²	Dec. 31, 2018 USD ($)	Apr. 04, 2017 ft²	Dec. 31, 2001 a
Loss Contingencies [Line Items]
Insurance maximum coverage per occurrence			$ 300,000,000
Insurance maximum coverage per property			300,000,000
Mortgages payable, net of deferred debt issuance costs			967,112,000				$ 965,826,000
Standby letters of credit, outstanding			$ 1,030,000
Paramus | IKEA | Tenant Occupant
Loss Contingencies [Line Items]
Area of land (in sqft.) | a									30.3
Fixed interest rate on the debt			4.72%
Triple-net rent, annual amount			$ 700,000
Mortgages payable, net of deferred debt issuance costs			$ 68,000,000
Debt instrument maturity date			Oct. 01, 2021
Rego Park I | Sears
Loss Contingencies [Line Items]
Area of property | ft²								195
Number of fires | fire		2
Annual property rental				$ 10,300,000
Rego Park I | Sears | Minimum
Loss Contingencies [Line Items]
Loss contingency, damages sought, value			$ 4,000,000
All Risk Property and Rental Value
Loss Contingencies [Line Items]
Insurance maximum coverage per occurrence			1,700,000,000
Terrorism Coverage Including NBCR
Loss Contingencies [Line Items]
Insurance maximum coverage per occurrence			1,700,000,000
Insurance maximum coverage in aggregate			$ 1,700,000,000
NBCR
Loss Contingencies [Line Items]
Insurance coverage end date			Dec. 01, 2020
Self insured responsibility			19.00%
Federal government responsibility			81.00%
NBCR | FNSIC
Loss Contingencies [Line Items]
Insurance deductible			$ 323,000
Forecast | Paramus | IKEA | Tenant Occupant
Loss Contingencies [Line Items]
Lease purchase option amount					$ 75,000,000
Purchase option not exercised amount included in triple net rent over remainder of lease					68,000,000
Purchase option exercised, net cash proceeds from sale of land					7,000,000
Purchase option exercised, gain on sale of land					$ 60,000,000
Lease term range as Lessor					20 years
Loan amortization period					20 years
Estimated Future Damages | Rego Park I | Sears
Loss Contingencies [Line Items]
Loss contingency, damages sought, value	$ 650,000
Estimated Future Damages | Rego Park I | Sears | Minimum
Loss Contingencies [Line Items]
Loss contingency, damages sought, value			25,000,000
Estimated Future Damages | Rego Park I | Sears | Maximum
Loss Contingencies [Line Items]
Reasonably possible losses			$ 650,000
Subsequent Event | Kohls
Loss Contingencies [Line Items]
Area of property | ft²						133