Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Additional Information (Detail)

v2.4.1.9
Stockholders' Equity - Additional Information (Detail)
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Class B Common Stock [Member]    
Class of Stock [Line Items]    
Certain Class B stockholders converted into Class A 255,522us-gaap_ConversionOfStockSharesConverted1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
10,296us-gaap_ConversionOfStockSharesConverted1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassBMember
Class A Common Stock [Member]    
Class of Stock [Line Items]    
Shares issued as a part of conversion 255,522us-gaap_ConversionOfStockSharesIssued1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
10,296us-gaap_ConversionOfStockSharesIssued1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember