Subsequent Events	9 Months Ended
Sep. 30, 2018
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	14. SUBSEQUENT EVENTS On October 16, 2018, the Company entered into an agreement to sell a portfolio of eight properties containing an aggregate of 1,293,197 square feet, located in the Metropolitan Washington, D.C. segment, for a gross sales price of $312.0 million. The Company will retain a 15% ownership interest in the properties through an unconsolidated real estate venture. After obtaining debt financing for the real estate venture, the Company anticipates receiving net cash receipts of approximately $292.0 million. As of September 30, 2018, the Portfolio was classified as held sale and the Company recorded an impairment of $56.9 million. As the properties were impaired to reflect the value of the estimated net cash proceeds, the Company does not anticipate a gain or loss upon settlement, which is expected to occur during the fourth quarter of 2018. For further information related to the impact to the consolidated balance sheets, see the “Held for Sale” section in Note 3, “Real Estate Investments.” On October 17, 2018, the Company entered into an agreement to acquire its partner's entire 50% interest in the 12 remaining properties within the DRA Austin real estate venture, containing 1,570,123 square feet, located in Austin, Texas, for a gross sales price of $537.0 million. In connection with the acquisition, the Company will assume an estimated $245.8 million of mortgage debt. The Company expects the transaction to settle during the fourth quarter of 2018. As of September 30, 2018, the Company’s investment in the real estate venture is $14.4 million, and upon settlement, the Company expects to recognize a gain on the transaction, which will be reflected in the caption ‘Net gain on real estate transactions’ in its consolidated statements of operations.

Subsequent Events

9 Months Ended

Sep. 30, 2018

14. SUBSEQUENT EVENTS

On October 16, 2018, the Company entered into an agreement to sell a portfolio of eight properties containing an aggregate of 1,293,197 square feet, located in the Metropolitan Washington, D.C. segment, for a gross sales price of $312.0 million. The Company will retain a 15% ownership interest in the properties through an unconsolidated real estate venture. After obtaining debt financing for the real estate venture, the Company anticipates receiving net cash receipts of approximately $292.0 million. As of September 30, 2018, the Portfolio was classified as held sale and the Company recorded an impairment of $56.9 million. As the properties were impaired to reflect the value of the estimated net cash proceeds, the Company does not anticipate a gain or loss upon settlement, which is expected to occur during the fourth quarter of 2018. For further information related to the impact to the consolidated balance sheets, see the “Held for Sale” section in Note 3, “Real Estate Investments.”

On October 17, 2018, the Company entered into an agreement to acquire its partner's entire 50% interest in the 12 remaining properties within the DRA Austin real estate venture, containing 1,570,123 square feet, located in Austin, Texas, for a gross sales price of $537.0 million. In connection with the acquisition, the Company will assume an estimated $245.8 million of mortgage debt. The Company expects the transaction to settle during the fourth quarter of 2018. As of September 30, 2018, the Company’s investment in the real estate venture is $14.4 million, and upon settlement, the Company expects to recognize a gain on the transaction, which will be reflected in the caption ‘Net gain on real estate transactions’ in its consolidated statements of operations.