Stock Plans (Details Textual) (USD $)	9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended			9 Months Ended
	Sep. 30, 2014 share_based_compensation_plan	Sep. 30, 2013	Sep. 30, 2014 Outstanding options to purchase common stock	Sep. 30, 2013 Outstanding options to purchase common stock	Sep. 30, 2014 Outstanding options to purchase common stock	Sep. 30, 2013 Outstanding options to purchase common stock	Sep. 30, 2014 Restricted Stock Awards	Sep. 30, 2013 Restricted Stock Awards	Sep. 30, 2014 Restricted Stock Awards	Sep. 30, 2013 Restricted Stock Awards	Sep. 30, 2014 Restricted stock unit awards	Sep. 30, 2013 Restricted stock unit awards	Sep. 30, 2014 Restricted stock unit awards	Sep. 30, 2013 Restricted stock unit awards	Sep. 30, 2014 Employee Stock Purchase Plan	Sep. 30, 2013 Employee Stock Purchase Plan	Sep. 30, 2014 Employee Stock Purchase Plan	Sep. 30, 2013 Employee Stock Purchase Plan	Jun. 30, 2013 Chief Financial Officer [Member]	Sep. 30, 2014 Director [Member] Restricted stock unit awards	Sep. 30, 2013 Director [Member] Restricted stock unit awards	Sep. 30, 2014 Director [Member] Restricted stock unit awards	Sep. 30, 2013 Director [Member] Restricted stock unit awards	Sep. 30, 2014 Service Based Restricted Stock [Member] Restricted stock unit awards	Sep. 30, 2014 Performance Based Restricted Stock [Member] Restricted stock unit awards
Stock Plans (Textual) [Abstract]
Stock-based compensation plans	2
Stock-based compensation expense	$ 2,934,000	$ 2,622,000	$ 33,000	$ (32,000)	$ 74,000	$ 307,000									$ 57,000	$ 0	$ 400,000	$ 0		$ 146,000	$ 188,000	$ 467,000	$ 440,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross																			75,000
Restricted stock granted							62,500	0	255,600	367,643
Restricted stock unit, granted											0	0	137,000							0	0	65,891	69,594	67,000	70,000
Restricted stock, average grant date fair value per share							$ 9.14		$ 14.20	$ 10.42												$ 9.03	$ 10.25	$ 15.17	$ 7.71
Discount rate from market value on offering date																		85.00%
Restricted stock unit vesting period (in years)														1 year