Restructuring Liabilities (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Restructuring activities
Restructuring expense (income)	$ 2,128	$ (270)	$ (1,144)	$ 5,918
Kendall Restructuring
Restructuring activities
Liability, beginning of the period	9,506	18,324	11,596	19,115
Cash payments	(2,584)	(3,960)	(6,569)	(7,822)
Cash received from subleases	2,799	2,689	5,275	5,378
Restructuring expense (income)	203	(2,117)	(378)	(1,735)
Liability, end of the period	9,924	14,936	9,924	14,936
Fan Pier Move Restructuring
Restructuring activities
Liability, beginning of the period	11,137	3,722	33,390	797
Cash payments	(3,095)	(2,143)	(22,351)	(4,377)
Restructuring expense (income)	975	1,677	(2,022)	6,836
Liability, end of the period	9,017	3,256	9,017	3,256
Other Restructuring
Restructuring activities
Liability, beginning of the period	845	1,821	869	8,441
Cash payments	(893)	(1,199)	(1,223)	(8,466)
Restructuring expense (income)	950	170	1,256	817
Liability, end of the period	$ 902	$ 792	$ 902	$ 792