Transactions with Related Parties	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Transactions with Related Parties	We lease office space from Two North Riverside Plaza Joint Venture Limited Partnership, an entity affiliated with Samuel Zell, Chairman of our Board of Directors. Payments made in accordance with the lease agreement to this entity amounted to approximately $1.6 million for the year ended December 31, 2020, $1.7 million for the year ended December 31, 2019, and $1.4 million for the year ended December 31, 2018.