Held for Sale/Disposed Assets - Narrative (Details) - Disposed of by sale $ in Millions	9 Months Ended
	Sep. 30, 2020 USD ($) property	Sep. 30, 2019 USD ($) property
Los Angeles
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties sold | property		1
Los Angeles | Disposed Assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net book value		$ 12.4
Gain on sale of real estate		$ 4.5
Washington D.C.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties sold | property	3
Washington D.C. | Disposed Assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales price	$ 17.8
Gain on sale of real estate	$ 51.3
Miami
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties sold | property	1	1
Miami | Disposed Assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sales price	$ 22.2	$ 14.0
Gain on sale of real estate	$ 9.0	$ 1.8