XML 43 R62.htm IDEA: XBRL DOCUMENT v2.4.0.6
Fair Value of Stock Option Awards Using a Binomial Option-Pricing Model (Detail)
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Risk-free interest rate 1.99% 3.49% 3.77%
Expected volatility 78.80% 78.80% 70.10%
Expected dividend yield 0.00% 0.00% 0.00%
Expected term 5 years 5 years 6 years