Stock Option and Purchase Plans (Details 1)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary of weighted-average assumptions
Dividend Yield	0.00%	0.00%	0.00%
Maximum [Member]
Summary of weighted-average assumptions
Risk-free Interest Rate	1.00%	2.82%	3.04%
Volatility Factor	0.64%	0.53%	0.53%
Expected Life in Years	8 years	8 years	8 years
Minimum [Member]
Summary of weighted-average assumptions
Risk-free Interest Rate	0.89%	1.55%	2.33%
Volatility Factor	0.52%	0.52%	0.41%
Expected Life in Years	5 years	7 years	7 years