The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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The aggregate costs of keeping the property in good condition but that do not appreciably prolong the life or increase the value of the property.

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For an unclassified balance sheet, the accumulated amortization, as of the reporting date, which represents the periodic charge to earnings of initial direct costs which have been deferred and are being allocated over the lease term in proportion to the recognition of rental income.

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The charge against earnings in the period to reduce the carrying amount of real property to fair value.

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Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Amount of real estate investment property which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Real Estate Transactions - Narrative (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Real Estate [Line Items]
Assets placed in service	$ 2,111,070,000		$ 2,081,597,000
Deferred leasing costs, net	27,057,000		24,083,000
Accumulated amortization deferred leasing cost	43,400,000		$ 41,600,000
Depreciation expense	21,200,000	$ 20,000,000.0
Repairs and maintenance expense	5,200,000	6,600,000
Impairment of real estate	$ 0
Building \| Minimum
Real Estate [Line Items]
Estimated useful life (in years)	35 years
Building \| Maximum
Real Estate [Line Items]
Estimated useful life (in years)	50 years
Building Improvements \| Maximum
Real Estate [Line Items]
Estimated useful life (in years)	20 years
Lease Acquisition Costs
Real Estate [Line Items]
Amortization of intangible assets	$ 2,700,000	$ 3,200,000
The Waycroft and Ashbrook Marketplace
Real Estate [Line Items]
Assets placed in service	$ 253,700,000