Related Party Transactions (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Amounts due from/to related parties
Due from joint ventures	$ 1,443		$ 1,443		$ 1,334
Other	11,616		11,616		9,316
Related party receivables	13,059		13,059		$ 10,650
Alliance Building Services
Related Party Transactions
Profit participation from related party	900	$ 1,000	1,700	$ 1,900
Payments made for services	7,100	4,600	10,900	8,600
Entity with Stephen L Green ownership interest
Related Party Transactions
Property management fees from related party	$ 100	$ 200	$ 100	$ 200