Component of Rental Income and Expense Components of Rental Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Rental Income [Line Items]
Cost reimbursement	$ 33,610	$ 30,796	$ 29,052
Percentage rent	3,096	2,834	3,107
Hotel revenue	39,371	38,191	33,911
Other	1,512	1,492	1,681
Total rental income	279,498	261,887	246,078
Total Retail
Rental Income [Line Items]
Minimum rents	74,050	72,999	70,573
Total Office
Rental Income [Line Items]
Minimum rents	90,281	87,125	82,018
Total Multifamily
Rental Income [Line Items]
Minimum rents	26,962	18,137	15,732
Total Mixed-Use
Rental Income [Line Items]
Minimum rents	$ 10,616	$ 10,313	$ 10,004