Fee and Other Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Fee And Other Income
BMS cleaning fees	$ 21,294	$ 18,794	$ 43,290	$ 36,940
Management and leasing fees	4,892	4,604	9,529	9,403
Lease termination fees	1,459	3,199	5,625	5,604
Other income	8,413	7,092	16,974	15,712
Fee and other income	36,058	33,689	75,418	67,659
Interstate Properties
Fee And Other Income
Management and leasing fees	$ 124	$ 128	$ 252	$ 262