Leases - Additional Information (Detail) ft² in Millions			3 Months Ended		12 Months Ended
	Mar. 12, 2019 ft² Property	Feb. 28, 2019 USD ($) Lease Option	Mar. 31, 2020 USD ($) Property	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) Property
Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items]
Right to recapture property space			50.00%
Number of real estate specified properties			5
Right to recapture property space exercised			100.00%
Number of real estate properties acquisition exercised					70
Number of terminated properties commenced or completed for redevelopment			46
Number of terminated properties sold			24
Number of properties subject to ground lease			1
Number of properties subject to corporate office lease			1
ROU assets | $			$ 19,800,000		$ 18,500,000
Operating leases expiration year			2073
General and Administrative Expenses [Member]
Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items]
Rent expense | $			$ 274,000	$ 285,000
Property Operating Expense
Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items]
Rent expense | $			$ 11,000	11,000
Sears Holdings Corporation [Member]
Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items]
Number of real estate properties acquisition exercised			87
Number of properties terminated under lease	31
Area of properties rejected under leases | ft²	4.3
Holdco [Member]
Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items]
Number of real estate properties acquisition exercised			29
Holdco Master Lease [Member]
Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items]
Lease expiration date		Jul. 31, 2025
Number of options for renewal of lease | Option		3
Renewal period of leases		5 years
Final option renewal period		4 years
Number of renewal term that will be increased | Lease		2
Percentage of increase annual lease rent		2.00%
Rent credit allocation description		The rent credit is allocated to specific properties based on the trailing twelve- month EBITDA of the particular property as of December 2018.
Number of real estate properties acquisition exercised					4
Lease termination, description			Under the terms of the Holdco Master Lease, Holdco has the right, at any time, to terminate the Holdco Master Lease with respect to any property upon the payment of a termination fee equal to one year of base rent plus annual taxes and other operating expenses.  Additionally, beginning in March 2020, the tenant has the right to terminate without payment of a termination fee: (i) up to 16 properties in the second year of the term of the Holdco Master Lease, (ii) up to 12 properties in the third year, (iii) up to 10 properties in the fourth year, and (iv) thereafter, the remaining properties, in each instance with carry over rights if less than the maximum permitted number of properties are terminated in any lease year.
Number of properties right to terminate without termination fee second year			16
Number of properties right to terminate without termination fee third year			12
Number of properties right to terminate without termination fee fourth year			10
Holdco Master Lease [Member] | Maximum [Member]
Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items]
Lease adjustment in form of rent credit | $		$ 12,000,000
Original and Holdco Master Lease [Member]
Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items]
Straight-line rental income | $			$ (4,500,000)	$ 500,000
Master Lease [Member]
Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items]
Right to recapture property space			100.00%
Number of properties to recapture			10
Right to recapture property space exercised			100.00%
Original Master Lease [Member]
Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items]
Number of real estate properties acquisition exercised					3