Assumptions used to Estimate Fair Value of Stock Option Granted (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013 Employee Stock Options 2013 Plan [Member]		Dec. 31, 2012 Employee Stock Options 2010 Plan [Member]		Dec. 31, 2011 Employee Stock Options 2010 Plan [Member]		Dec. 31, 2011 Employee Stock Options 2010 Plan [Member] Stock Options Not Granted
Share based Compensation Arrangement Assumptions Used to Estimate Fair Values of Share Options Granted [Line Items]
Stock Price	$ 23.36	[1]	$ 5.19	[1]	$ 1.30	[1]	$ 1.30	[1]
Risk-free rate	1.68%		0.59%		2.14%		2.06%
Expected volatility	36.56%		31.12%		35.00%		35.00%
Expected annual dividend yield	1.71%		0.00%		0.00%		0.00%
Expected term	6 years		3 years 10 months 13 days		4 years 7 months 6 days		4 years 5 months 27 days

[1] As discussed above, on May 9, 2012 an equitable adjustment to stock options was approved with caused a reduction of $7.41 per share of the exercise price of the outstanding options. Accordingly, the stock price presented above reflects this equitable adjustment for the periods of 2012 and 2011.