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Stock-based Compensation and Awards (Details 1)
12 Months Ended
Dec. 31, 2011
Y
Dec. 31, 2010
Y
Dec. 31, 2009
Y
Weighted average fair value at date of grant for options granted      
Expected life in years 4.5 4.5 4.5
Risk-free interest rate 1.23% 2.13% 1.84%
Volatility 45.17% 42.94% 40.51%
Dividend yield 0.00% 0.00% 0.00%