Restructuring Charges (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Severance	Dec. 31, 2013 Severance Maximum
Restructuring charges
Restructuring costs accrued and unpaid						$ 100,000
Stock option modification					100,000
Changes in restructuring liability
Balance at the beginning of the period					43,000
Severance and related costs	2,288,000	112,000	2,648,000	2,334,000	2,592,000
Cash payments					(1,226,000)
Balance at the end of the period					$ 1,409,000