Investment In and Advances to Affiliate - Additional Information (Detail) - Retail Value Inc. [Member] - Series A Preferred Stock [Member]	Jul. 01, 2018 USD ($) $ / shares
Aggregate Gross Proceeds of RVI's Asset Sales Subsequent to July 1, 2018 Exceeds $2.0 Billion [Member]
Investments In And Advances To Affiliates [Line Items]
Preferred stock, value	$ 190,000,000
Maximum increase in preferred stock amount	10,000,000
Threshold limit for proceeds from sale of real estate investment property	$ 2,000,000,000.0
To Redeem RVI Preferred Shares Upon Aggregate Dividends Payments Equalling $200 Million [Member]
Investments In And Advances To Affiliates [Line Items]
Preferred stock, redemption price | $ / shares	$ 1.00
Maximum [Member] | To Redeem RVI Preferred Shares Upon Aggregate Dividends Payments Equalling $200 Million [Member]
Investments In And Advances To Affiliates [Line Items]
Preferred stock, value	$ 200,000,000