Acquired Intangible Assets and Liabilities - Narrative (Details) - USD ($) $ in Thousands		12 Months Ended
	Mar. 09, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired leases		$ (10,500)	$ (17,100)	$ (27,300)
Expected average remaining lives (in years)	20 years
Amortization of customer relationship value, acquired in-place lease value and deferred leasing costs		$ 355,841	354,302	416,621
Customer Relationship Value
Finite-Lived Intangible Assets [Line Items]
Expected average remaining lives (in years)		15 years
Amortization of customer relationship value, acquired in-place lease value and deferred leasing costs		$ 166,500	128,400	123,500
Weighted average remaining contractual life for acquired leases excluding renewals or extensions (in years)		14 years 8 months 12 days
Acquired in-place lease value
Finite-Lived Intangible Assets [Line Items]
Expected average remaining lives (in years)		5 years 8 months 12 days
Amortization of customer relationship value, acquired in-place lease value and deferred leasing costs		$ 99,700	$ 143,000	$ 211,000
Weighted average remaining contractual life for acquired leases excluding renewals or extensions (in years)		5 years 6 months
Below-Market Leases, Net of Above-Market Leases
Finite-Lived Intangible Assets [Line Items]
Expected average remaining lives of acquired below market leases (in years)		7 years 2 months 12 days
Expected average remaining lives (in years)		2 years