Disposals of Operating Properties and Impairment Charge	9 Months Ended
Disposals of Operating Properties and Impairment Charge	Sep. 30, 2020
Discontinued Operations and Disposal Groups [Abstract]
Disposals of Operating Properties and Impairment Charge	Disposals of Operating Properties and Impairment Charge There were no operating properties sold during the nine months ended September 30, 2020. The Company sold one redevelopment property during the three months ended September 30, 2020 for gross proceeds of $14.0 million and a net gain of $3.1 million. The Company has not sold any other redevelopment properties during the nine months ended September 30, 2020. During the three months ended September 30, 2019, we sold eight operating properties for aggregate gross proceeds of $213.3 million and a net loss of $5.7 million. During the three months ended June 30, 2019, we sold eight operating properties for aggregate gross proceeds of $244.0 million and a net gain of $24.1 million. During the three months ended March 31, 2019, we sold our Whitehall Pike operating property for aggregate gross proceeds of $13.5 million and a net gain of $6.6 million. As of September 30, 2019, in connection with the preparation and review of the financial statements, we evaluated one operating property for impairment and recorded an $8.5 million impairment charge due to changes during the quarter in facts and circumstances underlying the Company's expected hold period of the property. A shortening of an expected future hold period is considered an impairment indicator under applicable accounting rules, and this indicator caused us to further evaluate the carrying value of the property. We concluded the estimated undiscounted cash flows over the expected holding periods did not exceed the carrying value of the asset, leading to the charge during the quarter. We estimated the fair value of the property to be $12.6 million using the market approach by utilizing recent sales offers without adjustment. As of June 30, 2019, in connection with the preparation and review of the financial statements, we evaluated five operating properties for impairment and recorded impairment charges totaling $25.1 million due to changes in facts and circumstances underlying the Company's expected future hold periods of these properties. A shortening of the expected future hold period is considered an impairment indicator under applicable accounting rules, and this indicator caused us to further evaluate the carrying value of the property. We concluded the estimated undiscounted cash flows over the expected holding periods did not exceed the carrying value of each asset, leading to the charges during the quarter. We estimated the fair value of each property, which aggregated to $152.9 million, using the market approach by utilizing recent sales offers without adjustment. As of March 31, 2019, in connection with the preparation and review of the financial statements, we evaluated an operating property for impairment and recorded a $4.1 million impairment charge due to changes in our estimate of the fair value for a property in which we had previously concluded that undiscounted cash flows were insufficient to recover the carrying value. We estimated the fair value of the property to be $10.0 million using the market approach by utilizing a recent sales offer without adjustment. We compared the estimated fair value to the carrying value, which resulted in the recording of a non-cash impairment charge of $4.1 million for the three months ended March 31, 2019. This property was sold in May 2019.