Restructuring and Special Charges (Rollforward of accrued liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Restructuring Reserve [Roll Forward]
Beginning balance	$ 10,901		$ 14,900
Additions	1,361	$ 6,100	6,531	$ 11,405
Adjustments to accruals	(391)		(933)
Cash payments	(5,351)		(13,978)
Ending balance	6,520		6,520
Deferred rent
Restructuring Reserve [Roll Forward]
Beginning balance	3,381		3,571
Additions	0		1,271
Adjustments to accruals	(391)		(933)
Cash payments	0		(919)
Ending balance	2,990		2,990
Accrued compensation and related costs
Restructuring Reserve [Roll Forward]
Beginning balance	3,566		7,006
Additions	382		2,751
Adjustments to accruals	0		0
Cash payments	(1,769)		(7,578)
Ending balance	2,179		2,179
Accounts payable
Restructuring Reserve [Roll Forward]
Beginning balance	805		1,066
Additions	1,380		3,018
Adjustments to accruals	0		0
Cash payments	(2,025)		(3,924)
Ending balance	160		160
Other accrued liabilities
Restructuring Reserve [Roll Forward]
Beginning balance	3,149		3,257
Additions	(401)		(509)
Adjustments to accruals	0		0
Cash payments	(1,557)		(1,557)
Ending balance	$ 1,191		$ 1,191