Stock Plans (Details 1) (Employee Stock Purchase Plan [Member], USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Stock Purchase Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum employee contribution to ESPP	$ 25
Maximum employee contribution to ESPP, percent of base compensation	10.00%
Common Stock Discount Purchase Price	95.00%
Shares Available Under Employee Stock Purchase Plan	4,550,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans	12,770	14,979	27,949
Proceeds from Stock Plans	$ 436	$ 457	$ 646
Number Of Shares Available Under Employee Stock Purchase Plan	308,455