Stockholders' Equity - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 07, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Stockholders Equity [Line Items]
Cash dividend declared monthly (per share)		$ 0.005
Stock repurchase program, authorized amount	$ 2,750,000.00					$ 2,750,000.00
Payments for repurchase of common stock				109,737	0
Stock-based compensation expense		610	610	1,220	8,320
Unrecognized share-based compensation cost		6,507	8,947	6,507	8,947
Number of options, options outstanding		29,000		29,000
Weighted average exercise price, options outstanding		$ 17.03		$ 17.03
Number of options, options exercisable		26,000		26,000
Weighted average exercise price, options exercisable		$ 18.25		$ 18.25
Common Class A
Stockholders Equity [Line Items]
Repurchased shares		28,227		41,446
Payments for repurchase of common stock		$ 72,528		$ 109,737