Held for Sale/Disposed Assets (Details) $ in Millions	12 Months Ended
	Dec. 31, 2023 USD ($) property	Dec. 31, 2022 USD ($) property	Dec. 31, 2021 USD ($) property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Number of properties (property) | property	259
Disposed of by Sale | Northern New Jersey/New York
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Number of properties (property) | property	2	3	1
Proceeds from sale of real estate	$ 43.2	$ 159.7	$ 32.7
Gain on sale of real estate	$ 21.9	$ 107.1	13.4
Disposed of by Sale | Washington D.C.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Number of properties (property) | property	1
Proceeds from sale of real estate	$ 18.0
Gain on sale of real estate	$ 9.7
Disposed of by Sale | Los Angeles
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Number of properties (property) | property	1
Proceeds from sale of real estate	$ 15.9
Gain on sale of real estate	$ 6.6
Disposed of by Sale | Seattle
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Number of properties (property) | property		1
Proceeds from sale of real estate		$ 8.6	10.3
Gain on sale of real estate		$ 5.1	$ 3.2