Significant Accounting Policies - Summary of Weighted Average Assumptions (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Share Based Payment Award Stock Options Valuation Assumptions [Line Items]
Risk-free interest rate	1.10%	1.10%	2.50%
Expected volatility	58.00%	59.90%	61.90%
Expected term	6 years 1 month 6 days	6 years 1 month 6 days	6 years 1 month 6 days
Weighted-average fair value per share	$ 10.99	$ 7.74	$ 7.76
Minimum [Member]
Schedule Of Share Based Payment Award Stock Options Valuation Assumptions [Line Items]
Expected dividend yield	0.80%	0.00%
Maximum [Member]
Schedule Of Share Based Payment Award Stock Options Valuation Assumptions [Line Items]
Expected dividend yield	1.10%	1.30%