Quarterly report pursuant to Section 13 or 15(d)

Share-Based Payment Award Activity (Parenthetical) (Detail)

v2.4.0.6
Share-Based Payment Award Activity (Parenthetical) (Detail) (USD $)
Sep. 30, 2012
Jun. 30, 2012
Dec. 31, 2011
Intrinsic value represents the excess of the closing stock price related to options outstanding $ 12.81 $ 10.48 $ 7.40