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Basic and Diluted Earnings Per Common Share - Additional Information (Detail) (USD $)
3 Months Ended
Mar. 31, 2014
Class A Common Stock
Dec. 31, 2013
Class A Common Stock
Mar. 31, 2013
Class A Common Stock
Mar. 31, 2014
Restricted Stock
Mar. 31, 2013
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]          
Common Stock, par value (usd per share) $ 0.01 $ 0.01 $ 0.01    
Anti-dilutive unvested restricted stock, shares       108,854 0