Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Amounts due from/to related parties
Due from joint ventures	$ 1,334	$ 1,254
Other	9,316	10,481
Related party receivables	10,650	11,735
Alliance Building Services
Related Party Transactions
Profit participation from related party	3,800	3,800	$ 3,500
Payments made for services	21,300	21,500	23,400
Entity with Stephen L Green ownership interest
Related Party Transactions
Property management fees from related party	$ 500	$ 400	$ 400