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Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | 12 Months Ended | 3 Months Ended | 3 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Mar. 31, 2014
Segment
Unit
|
Dec. 31, 2013
Unit
|
Mar. 31, 2014
Minimum
|
Mar. 31, 2013
Maximum
|
Mar. 31, 2014
Leasehold Improvements
|
Mar. 31, 2014
Other Fixed Assets
Minimum
|
Mar. 31, 2014
Other Fixed Assets
Maximum
|
Mar. 31, 2014
Class A Common Stock
|
Jun. 26, 2013
Class A Common Stock
|
Mar. 31, 2014
Class B Common Stock
|
Mar. 31, 2014
Slp
Class B Common Stock
|
|
| Summary Of Significant Accounting Policies [Line Items] | |||||||||||
| Ownership percentage in a subsidiary | 63.00% | 63.00% | |||||||||
| 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 | |||||||||