Restructuring Charges (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Severance	Dec. 31, 2013 Severance Maximum
Restructuring charges
Restructuring costs accrued and unpaid			$ 100,000	$ 100,000
Changes in restructuring liability
Balance at the beginning of the period			43,000
Severance and related costs	200,000	1,801,000	200,000
Cash payments			(122,000)
Balance at the end of the period			$ 121,000