COVID-19 Pandemic	12 Months Ended
COVID-19 Pandemic	Dec. 31, 2020
Unusual or Infrequent Items, or Both [Abstract]
COVID-19 Pandemic	COVID-19 Pandemic Our business has been adversely affected as a result of the COVID-19 pandemic and the preventive measures taken to curb the spread of the virus. Some of the effects on us include the following: •With the exception of grocery stores and other "essential" businesses, many of our retail tenants closed their stores in March 2020 and began reopening when New York City entered phase two of its reopening plan on June 22, 2020, however, there continue to be limitations on occupancy and other restrictions that affect their ability to resume full operations. •While our buildings remain open, many of our office tenants are working remotely. •We have closed the Hotel Pennsylvania. In connection with the closure, we accrued $9,246,000 of severance for furloughed Hotel Pennsylvania union employees and recognized a corresponding $3,145,000 income tax benefit for the year ended December 31, 2020. •We cancelled trade shows at theMART from late March through the remainder of 2020 and expect to resume in 2021. •Because certain of our development projects were deemed "non-essential," they were temporarily paused in March 2020 due to New York State executive orders and resumed once New York City entered phase one of its state mandated reopening plan on June 8, 2020. •As of April 30, 2020, we placed 1,803 employees on furlough, which included 1,293 employees of BMS, 414 employees at the Hotel Pennsylvania and 96 corporate staff employees. As of February 10, 2021, 50% of furloughed employees have returned to work. The remaining employees still on furlough are from BMS and the Hotel Pennsylvania. •Effective April 1, 2020, our executive officers waived portions of their annual base salary for the remainder of 2020. •Effective April 1, 2020, each non-management member of our Board of Trustees agreed to forgo their $75,000 annual cash retainer for the remainder of 2020. While we believe our tenants are required to pay rent under their leases and we have commenced legal proceedings against certain tenants that have failed to pay rent under their leases, in limited circumstances, we have agreed to and may continue to agree to rent deferrals and rent abatements for certain of our tenants. We have made a policy election in accordance with the Financial Accounting Standards Board (“FASB”) Staff Q&A which provides relief in accounting for leases during the COVID-19 pandemic, allowing us to continue recognizing rental revenue on a straight-line basis for rent deferrals, with no impact to revenue recognition, and to recognize rent abatements as a reduction to rental revenue in the period granted. See Note 3 - Basis of Presentation and Significant Accounting Policies for additional information. 2. COVID-19 Pandemic - continued Based on our assessment of the probability of rent collection of our lease receivables, we have written off $51,571,000 of receivables arising from the straight-lining of rents for the year ended December 31, 2020, including the JCPenney retail lease at Manhattan Mall and the New York & Company, Inc. office lease at 330 West 34th Street. Both tenants have filed for Chapter 11 bankruptcy and rejected their leases during 2020. In addition, we have written off $22,546,000 of tenant receivables deemed uncollectible for the year ended December 31, 2020. These write-offs resulted in a reduction of lease revenues and our share of income from partially owned entities. Prospectively, revenue recognition for lease receivables deemed uncollectible will be based on actual amounts received. See Note 4 - Revenue Recognition and Note 7 - Investments in Partially Owned Entities for additional information.