Share Capital - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014 Class A Stock [Member]	Mar. 31, 2014 Class A Stock [Member]	Dec. 31, 2013 Class A Stock [Member]	Jun. 30, 2013 Class A Stock [Member]	Mar. 31, 2013 Class A Stock [Member]	Dec. 31, 2012 Class A Stock [Member]	Oct. 07, 2011 Class A Stock [Member]	Jun. 30, 2014 Class B Stock [Member]	Dec. 31, 2013 Class B Stock [Member]
Class of Stock [Line Items]
Preferred stock, authorized	50,000,000
Preferred stock, par value	$ 0.001
Preferred stock, issued	0
Common stock, authorized		50,000,000							99,680
Common stock, par value		$ 0.001							$ 0.001
Common stock, issued		13,519,126		13,377,967				13,572,265	99,680	99,680
Common stock, outstanding		13,519,126	13,516,626	13,377,967	13,496,783	13,508,318	13,508,318	13,572,265	99,680	99,680
Repurchase of class A common stock								675,000
Percentage of repurchase of class A common stock								5.00%
Number of shares buy back	0
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	352,823