Employee Stock Purchase Plan (Details Textual)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Employee Stock Purchase Plan (Textual) [Abstract]
Open window for employees to enroll in the ESPP	every 6 months
2011 ESPP [Member]
Employee Stock Purchase Plan (Textual) [Abstract]
Adoption date of Employee Stock Purchase Plan	May 12, 2011
Term life of the employee stock purchase plan	10 years
Minimum number of days employees need to work to participate in the ESPP	90 days
Minimum number of hours per week employees need to work to participate in the ESPP	20 hours
Minimum number of months per year employees need to work to participate in the ESPP	5 months
Discount off the lower of the stock price on the first day or the last day of the 6 month period at which employees may purchase stock under the ESPP	15.00%
Number of shares of common stock reserved for issuance	1,200,000
Number of shares issued under the ESPP	73,717
Total number of shares available for issuance	1,126,283
2001 ESPP [Member]
Employee Stock Purchase Plan (Textual) [Abstract]
Adoption date of Employee Stock Purchase Plan	Feb. 15, 2001
Number of shares issued under the ESPP	0	88,343	97,332