Fee and Other Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fee And Other Income [Line Items]
BMS cleaning fees	$ 18,563	$ 22,467	$ 62,937	$ 63,618
Management and leasing fees	4,045	4,266	12,511	15,859
Lease termination fees	1,517	3,300	8,157	11,422
Other income	10,036	7,746	29,393	23,631
Fee and other income	34,161	37,779	112,998	114,530
Interstate Properties [Member]
Fee And Other Income [Line Items]
Management and leasing fees	$ 132	$ 132	$ 403	$ 397