Related Person Transactions	9 Months Ended
Sep. 30, 2017
Related Party Transactions [Abstract]
Related Person Transactions	Related Person Transactions The following discussion includes a description of our related person transactions for the nine months ended September 30, 2017 and 2016. Two North Riverside Plaza Joint Venture Limited Partnership: We have a lease with Two North Riverside Plaza Joint Venture Limited Partnership, an entity associated with Mr. Zell, our Chairman, to occupy office space on the twentieth and twenty-first floors of Two North Riverside Plaza in Chicago, Illinois (20th/21st Floor Office Lease). The initial term of the lease is approximately five years, with one 5-year renewal option. We have completed improvements to the office space utilizing the $0.7 million tenant improvement allowance pursuant to the lease. In connection with the 20th/21st Floor Office Lease, we also have a lease with Two North Riverside Plaza Joint Venture Limited Partnership for storage space in the basement of Two North Riverside Plaza. The lease expires December 31, 2020; however, each party has the right to terminate on 30 days' prior written notice. During the three months ended September 30, 2017 and 2016, we recognized expense of $0.2 million and $0.2 million, respectively, and during the nine months ended September 30, 2017 and 2016, we recognized expense of $0.6 million and $0.6 million, respectively, pursuant to the 20^th/21^st Floor Office Lease and the related storage space. Related/Corvex: On July 31, 2014, at our 2014 annual meeting of shareholders, our shareholders voted to approve the reimbursement of approximately $33.5 million of verified expenses incurred by Related Fund Management, LLC and Corvex Management LP (Related/Corvex) beginning February 2013 in connection with their consent solicitations to remove our former Trustees, elect the new Board of Trustees and to engage in related litigation. We paid approximately $16.7 million during the year ended December 31, 2014. Approximately $8.4 million was to be reimbursed only if the average closing price of our common shares was at least $26.00 (as adjusted for any share splits or share dividends) during the one year period after the date on which the reimbursement was approved by shareholders, and up to $8.4 million was to be reimbursed only if the average closing price of our common shares was at least $26.00 (as adjusted for any share splits or share dividends) during the one year period between the first and second anniversaries of the date on which the reimbursement was approved by shareholders. The average closing price of our common shares was at least $26.00 during both the first and second one year periods after the date on which the reimbursement was approved by shareholders, and as a result, in August 2016 and 2015 we paid an $8.2 million final payment and $8.4 million, respectively, to Related/Corvex.

Related Person Transactions

The following discussion includes a description of our related person transactions for the nine months ended September 30, 2017 and 2016.

Two North Riverside Plaza Joint Venture Limited Partnership: We have a lease with Two North Riverside Plaza Joint Venture Limited Partnership, an entity associated with Mr. Zell, our Chairman, to occupy office space on the twentieth and twenty-first floors of Two North Riverside Plaza in Chicago, Illinois (20th/21st Floor Office Lease). The initial term of the lease is approximately five years, with one 5-year renewal option. We have completed improvements to the office space utilizing the $0.7 million tenant improvement allowance pursuant to the lease. In connection with the 20th/21st Floor Office Lease, we also have a lease with Two North Riverside Plaza Joint Venture Limited Partnership for storage space in the basement of Two North Riverside Plaza. The lease expires December 31, 2020; however, each party has the right to terminate on 30 days' prior written notice. During the three months ended September 30, 2017 and 2016, we recognized expense of $0.2 million and $0.2 million, respectively, and during the nine months ended September 30, 2017 and 2016, we recognized expense of $0.6 million and $0.6 million, respectively, pursuant to the 20^th/21^st Floor Office Lease and the related storage space.

Related/Corvex: On July 31, 2014, at our 2014 annual meeting of shareholders, our shareholders voted to approve the reimbursement of approximately $33.5 million of verified expenses incurred by Related Fund Management, LLC and Corvex Management LP (Related/Corvex) beginning February 2013 in connection with their consent solicitations to remove our former Trustees, elect the new Board of Trustees and to engage in related litigation. We paid approximately $16.7 million during the year ended December 31, 2014. Approximately $8.4 million was to be reimbursed only if the average closing price of our common shares was at least $26.00 (as adjusted for any share splits or share dividends) during the one year period after the date on which the reimbursement was approved by shareholders, and up to $8.4 million was to be reimbursed only if the average closing price of our common shares was at least $26.00 (as adjusted for any share splits or share dividends) during the one year period between the first and second anniversaries of the date on which the reimbursement was approved by shareholders. The average closing price of our common shares was at least $26.00 during both the first and second one year periods after the date on which the reimbursement was approved by shareholders, and as a result, in August 2016 and 2015 we paid an $8.2 million final payment and $8.4 million, respectively, to Related/Corvex.