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Significant Accounting Policies - Concentrations of Credit Risk/Accounting Standards Updates (Details) - Annualized rent - Customer concentration | 9 Months Ended
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Sep. 30, 2020 Tenant
Concentration of Credit Risk |
Number of tenants (tenants) | 1
Maximum percentage of annualized rent for any one tenant not individually disclosed (percent) (more than) | 5.00%
1185 Avenue of the Americas |
Concentration of Credit Risk |
Percentage of concentration (percent) | 8.40%
11 Madison Avenue |
Concentration of Credit Risk |
Percentage of concentration (percent) | 8.10%
420 Lexington Avenue |
Concentration of Credit Risk |
Percentage of concentration (percent) | 7.40%
1515 Broadway |
Concentration of Credit Risk |
Percentage of concentration (percent) | 6.30%
220 East 42nd Street |
Concentration of Credit Risk |
Percentage of concentration (percent) | 5.90%
280 Park Avenue |
Concentration of Credit Risk |
Percentage of concentration (percent) | 5.40%
485 Lexington Avenue |
Concentration of Credit Risk |
Percentage of concentration (percent) | 5.00%
Tenant 1 |
Concentration of Credit Risk |
Percentage of concentration (percent) | 5.50%

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