v2.4.0.8
Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
9 Months Ended 0 Months Ended
Sep. 30, 2013
Oct. 31, 2012
Oct. 07, 2013
Subsequent Event [Member]
Schedule Of Significant Accounting Policies [Line Items]      
Initial Contribution to the joint venture   $ 10  
Additional Contribution to the joint venture 8.3    
Gain on the sale of equity interest joint venture     91
Proceeds from sale of equity interest joint venture     $ 109.1