Annual report pursuant to Section 13 and 15(d)

Stock Plans (Details 2)

v2.4.0.6
Stock Plans (Details 2) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Schedule of assumptions used to estimate the share-based compensation expense      
Weighted-average risk-free interest rate 0.91% 2.30% 2.30%
Expected dividend payments $ 0 $ 0 $ 0
Expected holding period (years)(1) 5 years 1 month 6 days 5 years 4 months 24 days 4 years 2 months 12 days
Weighted-average volatility factor(2) 1.75 1.71 1.89
Estimated forfeiture rates for options granted to management(3) 23.00% 23.00% 23.00%
Estimated forfeiture rates for options granted to non-management(3) 41.00% 41.00% 41.00%