Restructuring Liabilities (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Restructuring activities
Restructuring (income) expense	$ (270)	$ 776	$ 5,918	$ 815
Kendall Restructuring
Restructuring activities
Liability, beginning of the period	18,324	22,459	19,115	23,328
Cash payments	(3,960)	(3,849)	(7,822)	(7,422)
Cash received from subleases	2,689	2,666	5,378	5,331
Restructuring (income) expense	(2,117)	776	(1,735)	815
Liability, end of the period	14,936	22,052	14,936	22,052
Fan Pier Move Restructuring
Restructuring activities
Liability, beginning of the period	3,722		797
Cash payments	(2,143)		(4,377)
Restructuring (income) expense	1,677		6,836
Liability, end of the period	3,256		3,256
Strategic Restructuring
Restructuring activities
Liability, beginning of the period	1,821		8,441
Cash payments	(1,199)		(8,466)
Restructuring (income) expense	170		817
Liability, end of the period	$ 792		$ 792