Fee and Other Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Fee And Other Income [Line Items]
BMS cleaning fees	$ 18,146	$ 22,633
Management and leasing fees	4,799	4,192
Lease termination fees	2,405	3,747
Other income	8,620	9,035
Fee and other income	33,970	39,607
Interstate Properties [Member]
Fee And Other Income [Line Items]
Management and leasing fees	$ 134	$ 139