Held for Sale/Disposed Assets (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) property	Dec. 31, 2018 USD ($) property
Held For Sale Assets [Line Items]
Number of properties | property	220
Held-for-sale [Member]
Held For Sale Assets [Line Items]
Number of properties | property	0
Disposed of by Sale [Member] | Disposed assets [Member] | Los Angeles [Member]
Held For Sale Assets [Line Items]
Number of properties sold | property	1	1
Proceeds from sale of property	$ 12.4	$ 33.2
Gain on sale of property	$ 4.5	$ 12.2
Disposed of by Sale [Member] | Disposed assets [Member] | Miami [Member]
Held For Sale Assets [Line Items]
Number of properties sold | property	1	2
Proceeds from sale of property	$ 14.0	$ 28.6
Gain on sale of property	$ 1.8	$ 13.1
Disposed of by Sale [Member] | Disposed assets [Member] | Washington D.C. [Member]
Held For Sale Assets [Line Items]
Number of properties sold | property	2	1
Proceeds from sale of property	$ 22.5	$ 20.3
Gain on sale of property	$ 3.1	$ 3.3