Fair Value Measures - Items Measured at Fair Value on a Non-Recurring Basis (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) property	Mar. 31, 2019 USD ($) property
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Properties impaired | property	16	24
Impairment charges | $	$ 8.4	$ 12.0
Measurement Input, Discount Rate [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement Input	0.079
Measurement Input, Cap Rate [Member] | Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Measurement Input	0.074