Stock Plans (Details)	12 Months Ended
	Dec. 31, 2011 Y	Dec. 31, 2010 Y	Dec. 31, 2009 Y
Weighted Average for key assumptions in determining the fair value of options granted
Expected Volatility, Minimum	68.20%	67.10%	54.60%
Expected Volatility, Maximum	68.20%	68.10%	64.50%
Weighted-Average expected volatility	68.20%	67.10%	56.20%
Expected dividends	0.00%	0.00%	0.00%
Expected term (in years), Minimum	5.1	4.9	5.0
Expected term (in years), Maximum	5.1	5.1	5.1
Risk-free rate, Minimum	2.10%	1.30%	1.90%
Risk-free rate, Maximum	2.10%	2.60%	2.70%