Annual report pursuant to section 13 and 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v2.4.0.8
Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
12 Months Ended 12 Months Ended
Dec. 31, 2013
Unit
Segment
Dec. 31, 2012
Unit
Dec. 31, 2013
Minimum
Dec. 31, 2012
Maximum
Dec. 31, 2013
Leasehold Improvements
Dec. 31, 2013
Other Fixed Assets
Minimum
Dec. 31, 2013
Other Fixed Assets
Maximum
Dec. 31, 2013
Class A Common Stock
Jun. 26, 2013
Class A Common Stock
Dec. 31, 2013
Class B Common Stock
Dec. 31, 2013
Slp
Class B Common Stock
Summary Of Significant Accounting Policies [Line Items]                      
Ownership percentage in a subsidiary               63.00% 63.00%    
Cash equivalents, maximum maturity period 90 days                    
Equity method investments, unrealized intercompany profit (loss) not eliminated amount $ 0                    
Property, plant and equipment, useful life         10 years 3 years 7 years        
Number of reporting unit 1 1                  
Identifiable finite-lived intangible assets, useful life     3 years 20 years              
Professional and other cost related to IPO   $ 2,816,000                  
Common stock voting rights               1 vote per share   1 vote per share  
Class of share exchangeable to another class                   One share of Class A common stock One share of Class A common stock
Number of operating segment 1