Real Estate Dispositions, Held for Sale and Impairment Charges - Components of Assets and Liabilities Held for Sale (Detail) - USD ($) $ in Thousands  | 
Sep. 30, 2020  | 
Dec. 31, 2019  | 
|---|---|---|
| Assets Held for Sale | ||
| Total Assets Held for Sale | $ 18,173 | $ 3,990 | 
| Liabilities Held for Sale | ||
| Total Liabilities Held for Sale | 1,108 | 21 | 
| Real Estate Held for Sale | ||
| Assets Held for Sale | ||
| Real estate, at cost | 24,688 | 7,411 | 
| Less: accumulated depreciation | 7,433 | 3,421 | 
| Total real estate held for sale, net | 17,255 | 3,990 | 
| Lease intangibles, net | 462 | 0 | 
| Deferred rent receivable, net | 456 | 0 | 
| Total Assets Held for Sale | 18,173 | 3,990 | 
| Liabilities Held for Sale | ||
| Deferred rent liability, net | 1,108 | 0 | 
| Asset retirement obligation | 0 | 21 | 
| Total Liabilities Held for Sale | $ 1,108 | $ 21 | 
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- Definition Disposal Group Including Discontinued Operation Asset Retirement Obligation No definition available. 
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- Definition Disposal Group, Including Discontinued Operation, Deferred Rent No definition available. 
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- Definition Disposal group including discontinued operation deferred rent receivables net. No definition available. 
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- Definition Disposal group including discontinued operation real estate investment property accumulated depreciation. No definition available. 
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- Definition Disposal group including discontinued operation real estate investment property at cost. No definition available. 
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- Definition Disposal group including discontinued operation real estate investment property net. No definition available. 
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- Definition Amount classified as assets attributable to disposal group held for sale or disposed of. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- References No definition available. 
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- Definition Amount classified as intangible assets, excluding goodwill, attributable to disposal group held for sale or disposed of. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount classified as liabilities attributable to disposal group held for sale or disposed of. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- References No definition available. 
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- Details 
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