Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation (Details)

v2.4.0.6
Share-Based Compensation (Details)
12 Months Ended
Dec. 31, 2011
Y
Dec. 31, 2010
Y
Dec. 31, 2009
Y
SARS [Member]
     
Weighted average assumptions used in the calculation of the fair value for service condition awards      
Expected volatility 46.60% 48.30% 48.50%
Dividends yield 1.50% 1.80% 5.70%
Expected term 6.2 6.4 6.5
Risk-free interest rate 1.90% 2.40% 2.30%
Independent Director's SARS [Member]
     
Weighted average assumptions used in the calculation of the fair value for service condition awards      
Expected volatility 49.40% 48.20% 48.60%
Dividends yield 1.50% 1.70% 5.80%
Expected term 3.8 3.8 3.8
Risk-free interest rate 1.00% 1.30% 1.40%