Intangible Assets and Below Market Lease Liabilities - Scheduled Future Amortization (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Scheduled future amortization of intangible assets [Abstract]
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	$ 216,329	$ 231,347
Scheduled future amortization of below market lease liabilities [Abstract]
Total scheduled future amortization of acquisition-related below market lease liabilities	(27,396)	$ (31,957)
Deferred Leasing Costs and Acquisition-Related Intangible Assets (in Depreciation and Amortization) [Member]
Scheduled future amortization of intangible assets [Abstract]
October 1 through December 31, 2020	9,338
2021	34,011
2022	29,936
2023	26,470
2024	23,322
Thereafter	77,046
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	$ 200,123
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Finite-lived intangible assets, average useful life (in years)	8 years 3 months 18 days
Lease Incentives (in Rental and Other Revenues) [Member]
Scheduled future amortization of intangible assets [Abstract]
October 1 through December 31, 2020	$ 460
2021	1,601
2022	1,392
2023	1,315
2024	1,170
Thereafter	5,631
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	$ 11,569
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Finite-lived intangible assets, average useful life (in years)	9 years 6 months
Acquisition-Related Intangible Assets (in Rental and Other Revenues) [Member]
Scheduled future amortization of intangible assets [Abstract]
October 1 through December 31, 2020	$ 244
2021	718
2022	601
2023	447
2024	373
Thereafter	2,161
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	$ 4,544
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Finite-lived intangible assets, average useful life (in years)	9 years 8 months 12 days
Acquisition-Related Intangible Assets (in Rental Property and Other Expenses) [Member]
Scheduled future amortization of intangible assets [Abstract]
October 1 through December 31, 2020	$ 93
2021	0
2022	0
2023	0
2024	0
Thereafter	0
Deferred leasing costs, net/Total scheduled future amortization of intangible assets	$ 93
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Finite-lived intangible assets, average useful life (in years)	2 months 12 days
Acquisition-Related Below Market Lease Liabilities (in Rental and Other Revenues) [Member]
Scheduled future amortization of below market lease liabilities [Abstract]
October 1 through December 31, 2020	$ (1,395)
2021	(5,013)
2022	(3,982)
2023	(3,607)
2024	(2,939)
Thereafter	(10,460)
Total scheduled future amortization of acquisition-related below market lease liabilities	$ (27,396)
Weighted average remaining amortization periods for intangible assets and below market lease liabilities [Abstract]
Finite-lived below market lease liabilities, average useful life (in years)	8 years 7 months 6 days