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Real Estate and Intangible Assets - Carrying Value of Intangible Assets and Accumulated Amortization (Detail) - USD ($) $ in Thousands | Jun. 30, 2021 | Dec. 31, 2020
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Finite-Lived Intangible Assets [Line Items] |  |
Below market leases and deferred revenue, gross | $ (39,481) | $ (38,319)
Below market leases and deferred revenue, accumulated amortization | 20,110 | 17,686
Lease Intangibles |  |
Finite-Lived Intangible Assets [Line Items] |  |
Lease Intangibles | 246,393 | 241,229
Accumulated Amortization | (135,309) | (123,850)
In-place leases |  |
Finite-Lived Intangible Assets [Line Items] |  |
Lease Intangibles | 100,779 | 99,254
Accumulated Amortization | (58,955) | (54,168)
Leasing costs |  |
Finite-Lived Intangible Assets [Line Items] |  |
Lease Intangibles | 76,602 | 73,707
Accumulated Amortization | (41,224) | (37,801)
Customer relationships |  |
Finite-Lived Intangible Assets [Line Items] |  |
Lease Intangibles | 69,012 | 68,268
Accumulated Amortization | (35,130) | (31,881)
Above market leases |  |
Finite-Lived Intangible Assets [Line Items] |  |
Lease Intangibles | 15,460 | 15,076
Accumulated Amortization | $ (11,097) | $ (10,670)

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- Definition Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
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