Restructuring Liabilities (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Restructuring activities
Restructuring expense (income)	$ 1,826	$ 40,843	$ 682	$ 46,761
Kendall Restructuring
Restructuring activities
Liability, beginning of the period	9,924	14,936	11,596	19,115
Cash payments	(3,975)	(4,249)	(10,544)	(12,071)
Cash received from subleases	2,919	2,689	8,194	8,067
Restructuring expense (income)	146	(464)	(232)	(2,199)
Liability, end of the period	9,014	12,912	9,014	12,912
Fan Pier Move Restructuring
Restructuring activities
Liability, beginning of the period	9,017	3,256	33,390	797
Cash payments	(3,070)	(2,266)	(25,421)	(6,643)
Cash received from subleases	1,820	0	1,820	0
Restructuring expense (income)	51	39,752	(1,971)	46,588
Liability, end of the period	7,818	40,742	7,818	40,742
Other Restructuring
Restructuring activities
Liability, beginning of the period	902	792	869	8,441
Cash payments	(1,559)	(399)	(2,782)	(8,865)
Restructuring expense (income)	1,629	1,555	2,885	2,372
Liability, end of the period	$ 972	$ 1,948	$ 972	$ 1,948