Investments in Unconsolidated Joint Ventures - Combined Condensed Statements of Operations of unconsolidated joint ventures (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues:
Leasing revenue	$ 210,721	$ 211,008
Expenses:
Company's equity in net income	9,698	12,243
Joint Venture
Revenues:
Leasing revenue	230,623	219,544
Other	6,939	12,246
Total revenues	237,562	231,790
Expenses:
Shopping center and operating expenses	71,151	69,322
Leasing expenses	1,768	2,174
Interest expense	54,235	53,862
Depreciation and amortization	96,978	89,981
Total operating expenses	224,132	215,339
Loss on sale or write down of assets, net		(141)
Net income	13,430	16,310
Company's equity in net income	9,698	12,243
Joint Venture | PPR Portfolio
Revenues:
Leasing revenue	58,378	46,020
Other	51	182
Total revenues	58,429	46,202
Expenses:
Shopping center and operating expenses	9,642	9,672
Leasing expenses	473	467
Interest expense	16,094	16,951
Depreciation and amortization	28,618	25,514
Total operating expenses	54,827	52,604
Loss on sale or write down of assets, net		(6)
Net income	3,602	(6,408)
Company's equity in net income	4,721	(1,199)
Joint Venture | Other Joint Ventures
Revenues:
Leasing revenue	172,245	173,524
Other	6,888	12,064
Total revenues	179,133	185,588
Expenses:
Shopping center and operating expenses	61,509	59,650
Leasing expenses	1,295	1,707
Interest expense	38,141	36,911
Depreciation and amortization	68,360	64,467
Total operating expenses	169,305	162,735
Loss on sale or write down of assets, net		(135)
Net income	9,828	22,718
Company's equity in net income	$ 4,977	$ 13,442