Tenant Leases (Future Minimum Rentals To Be Received Under Non-Cancelable Operating Leases) (Details) - USD ($) $ in Thousands  | 
3 Months Ended | |
|---|---|---|
Mar. 31, 2020  | 
Dec. 31, 2019  | 
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| Property Subject to or Available for Operating Lease [Line Items] | ||
| 2020 | $ 91,081 | $ 115,418 | 
| 2021 | 112,114 | 107,027 | 
| 2022 | 108,741 | 103,417 | 
| 2023 | 103,614 | 99,544 | 
| 2024 | 91,838 | 88,082 | 
| Thereafter | 514,091 | 488,305 | 
| Total | $ 1,021,479 | $ 1,001,793 | 
| Tenant Leases [Member] | ||
| Property Subject to or Available for Operating Lease [Line Items] | ||
| Operating leases with various expiration dates through year | 2036 | |
| Multi-Family Properties [Member] | ||
| Property Subject to or Available for Operating Lease [Line Items] | ||
| Lease period | 1 year | 
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- Definition Lease Expiration Year No definition available. 
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- Definition Lease Period No definition available. 
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- Definition Future minimum rental payments in aggregate as of the balance sheet date under operating leases. Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef 
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- Definition Future rental payments receivable within one year of the balance sheet date under an operating lease. Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef 
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- Definition Future rental payments receivable within the fourth year from the balance sheet date under an operating lease. Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef 
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- Definition Future rental payments receivable within the third year from the balance sheet date under an operating lease. Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef 
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- Definition Future rental payments receivable within the second year from the balance sheet date under an operating lease. Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef 
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- Definition Amount of required minimum rental payments receivable in the remainder of the fiscal year following the latest fiscal year ended for operating leases having an initial or remaining non-cancelable letter-terms in excess of one year. No definition available. 
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- Definition Future minimum lease payments receivable under operating leases for periods greater than five years following the balance sheet date. Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef 
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- Definition 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. No definition available. 
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- Details 
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- Details 
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