Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Detail)

v2.4.0.8
Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
6 Months Ended 12 Months Ended 6 Months Ended 6 Months Ended
Jun. 30, 2014
Segment
Unit
Dec. 31, 2013
Unit
Jun. 30, 2014
Minimum
Jun. 30, 2014
Maximum
Jun. 30, 2014
Leasehold Improvements
Jun. 30, 2014
Other Fixed Assets
Minimum
Jun. 30, 2014
Other Fixed Assets
Maximum
Jun. 30, 2014
Class A Common Stock
Jun. 26, 2013
Class A Common Stock
Jun. 30, 2014
Class B Common Stock
Jun. 30, 2014
Slp
Class B Common Stock
Summary Of Significant Accounting Policies [Line Items]                      
Ownership percentage in a subsidiary               62.00% 62.00%    
Number of operating segment 1                    
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              
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