Commitments and Contingencies - Narrative (Details) - USD ($)	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Real Estate Properties [Line Items]
General liability insurance limit	$ 200,000,000.0
Property and rental value insurance coverage limit	2,000,000,000.0
Terrorist acts insurance coverage limit	2,000,000,000.0
Purchase obligation	362,800,000
Environmental liabilities	17,898,000	$ 17,898,000
Additional capital funding committed amount	47,300,000
Consolidated Properties
Real Estate Properties [Line Items]
Purchase obligation	307,200,000
Principal payment guarantees	8,300,000
Unconsolidated Properties
Real Estate Properties [Line Items]
Purchase obligation	55,600,000
Principal payment guarantees	$ 0
Minimum
Real Estate Properties [Line Items]
Commitment amortization period	2 years
Maximum
Real Estate Properties [Line Items]
Commitment amortization period	3 years