v2.4.0.6
Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2013
Oct. 31, 2012
Schedule Of Significant Accounting Policies [Line Items]    
Initial Contribution to the joint venture   $ 10
Additional Contribution to the joint venture $ 6.3