Leases - Operating Leases - Additional Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($) item shopping_center	Mar. 31, 2018 USD ($)
Operating Leased Assets [Line Items]
Variable lease revenues	$ 13,300
Cumulative effect adjustment to retained earnings required upon adoption of the new standard	0
Operating lease, right-of-use asset	$ 11,871
Number of operating lease | item	9
Number of finance lease | item	4
Finance lease, right-of-use asset	$ 82,629
Number of shopping centers with land leases | shopping_center	6
Ground lease expense		$ 400
Rent expense capitalized		200
Rent expense		200
Capital lease term	49 years
Capital Lease Liability
Operating Leased Assets [Line Items]
Finance lease liabilities	$ 71,100
Repayments capital lease obligations		$ 600
Ground, Office and Equipment Leases
Operating Leased Assets [Line Items]
Operating lease, right-of-use asset	82,600
Operating lease liabilities	76,600
Capital Leases Asset
Operating Leased Assets [Line Items]
Finance lease, right-of-use asset	77,000
Accounting Standards Update 2016-02
Operating Leased Assets [Line Items]
Operating lease, right-of-use asset	11,900
Operating lease liabilities	12,800
Finance lease, right-of-use asset	$ 5,700
Minimum
Operating Leased Assets [Line Items]
Operating lease term	1 month
Period of lease term	25 years
Maximum
Operating Leased Assets [Line Items]
Operating lease term	60 years
Period of lease term	71 years