Commitments and Contingencies (Details 2) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Letter of Credit	Dec. 31, 2012 Letter of Credit	Jun. 30, 2013 Letter Of Credit Expired
Future Minimum Lease Payments
2013 (Remaining)	$ 3,889,000		$ 3,889,000
2014	6,590,000		6,590,000
2015	5,943,000		5,943,000
2016	5,487,000		5,487,000
2017	5,447,000		5,447,000
Thereafter	38,364,000		38,364,000
Total	65,720,000		65,720,000
Sublease Rental Income
2013 (Remaining)	775,000		775,000
2014	860,000		860,000
2015	502,000		502,000
Total	2,137,000		2,137,000
Net Lease Payments
2013 (Remaining)	3,114,000		3,114,000
2014	5,730,000		5,730,000
2015	5,441,000		5,441,000
2016	5,487,000		5,487,000
2017	5,447,000		5,447,000
Thereafter	38,364,000		38,364,000
Total	63,583,000		63,583,000
Lease restructuring charge	16,800,000
Rental expense, net of sublease rental income	200,000	200,000	300,000	400,000
Letters of Credit
Letters of Credit					$ 1,000,000	$ 4,900,000	$ 3,900,000