Restructuring Liabilities (Details) ft² in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2015 ft² lease	Sep. 30, 2014 facility	Dec. 31, 2003	Dec. 31, 2011 ft²
Restructuring Cost and Reserve [Line Items]
Area of real estate property (in square feet)				1,100
Kendall Restructuring
Restructuring Cost and Reserve [Line Items]
Lease term (in years)			15 years
Restructuring and related activities, leased office space, maximum percentage used - not more than			50.00%
Fan Pier Move Restructuring
Restructuring Cost and Reserve [Line Items]
Number of facilities decommissioned | facility		3
Number of leases terminated | lease	2
Area of real estate property (in square feet)	120
Discount rate related to leases (percent)	9.00%