Restructuring (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended	3 Months Ended	18 Months Ended	3 Months Ended	6 Months Ended	34 Months Ended	18 Months Ended	3 Months Ended	6 Months Ended				3 Months Ended		1 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2010 2008 plan employee	Jun. 30, 2010 2010 plan employee	Sep. 30, 2011 2010 plan employee	Mar. 31, 2012 2012 plan employee	Jun. 30, 2012 2012 plan employee	Sep. 30, 2011 Contract Termination [Member] 2008 plan	Sep. 30, 2011 Contract Termination [Member] 2010 plan	Mar. 31, 2012 Contract Termination [Member] 2012 plan	Jun. 30, 2012 Severance and related costs 2012 plan	Jun. 30, 2012 Contract termination and other associated costs 2008 plan	Jun. 30, 2012 Contract termination and other associated costs 2010 plan	Jun. 30, 2012 Contract termination and other associated costs 2012 plan	Jun. 30, 2010 Employee severance 2010 plan	Mar. 31, 2012 Employee severance 2012 plan	Jul. 31, 2012 Subsequent event 2008 plan
Restructuring Cost and Reserve [Line Items]
Number of positions terminated					70		25		24
Severance-related costs					$ 1,500,000
Contract termination costs										3,800,000	300,000
Abated rent and other operating expenses																			200,000
Expected percentage reduction in workforce						10.00%
Expected number of positions terminated						26		32
Expected restructuring cost												400,000					400,000	400,000
Restructuring cost, obligation through 2013																100,000
Restructuring Reserve [Roll Forward]
Accrued restructuring balance, beginning of period								0	0				0	1,212,000	116,000	0
Restructuring plan expense	73,000	37,000	674,000	(4,000)					721,000				355,000	29,000	3,000	366,000
Adjustments to restructuring plan									150,000				0	(73,000)	(4,000)	150,000
Cash payments									(574,000)				(281,000)	(400,000)	(41,000)	(293,000)
Accrued restructuring balance, end of period									$ 297,000				$ 74,000	$ 768,000	$ 74,000	$ 223,000