Reporting Segments and Related Information - Revenue Components of Real Estate Segments (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue from External Customer [Line Items]
Equity in earnings of unconsolidated joint ventures, net	$ 1,971	$ 652	$ 2,847	$ 819
Total expenses	10,341	7,419	22,035	19,343
Operating results from commercial and unconsolidated joint ventures	927	(1,361)	1,146	620
Real estate - commercial/industrial
Revenue from External Customer [Line Items]
Commercial revenues	6,595	2,189	9,421	4,343
Equity in earnings of unconsolidated joint ventures, net	1,971	652	2,847	819
Commercial revenues and equity in earnings of unconsolidated joint ventures	8,566	2,841	12,268	5,162
Total expenses	4,593	1,388	6,385	2,707
Operating results from commercial and unconsolidated joint ventures	$ 3,973	$ 1,453	$ 5,883	$ 2,455

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